Anti-complement C1s

ABSTRACT

The present disclosure provides antibodies that bind complement C1s protein; and nucleic acid molecules that encode such antibodies. The present disclosure also provides compositions comprising such antibodies, and methods to produce and use such antibodies, nucleic acid molecules, and compositions.

CROSS-REFERENCE

This application is a continuation of U.S. patent application Ser. No.14/070,186, filed Nov. 1, 2013, which application claims the benefit ofU.S. Provisional Patent Application Nos. 61/721,916, filed Nov. 2, 2012,61/754,123, filed Jan. 18, 2013, 61/779,180, filed Mar. 13, 2013, and61/846,402, filed Jul. 15, 2013, which applications are incorporatedherein by reference in their entirety.

INTRODUCTION

The complement system is a well-known effector mechanism of the immuneresponse, providing not only protection against pathogens and otherharmful agents but also recovery from injury. The complement pathwaycomprises a number of proteins that typically exist in the body ininactive form. The classical complement pathway is triggered byactivation of the first component of complement, referred to as the C1complex, which consists of C1q, C1r, and C1s proteins. Upon binding ofC1 to an immune complex or other activator, the C1s component, adiisopropyl fluorophosphate (DFP)-sensitive serine protease, cleavescomplement components C4 and C2 to initiate activation of the classicalcomplement pathway. The classical complement pathway appears to play arole in many diseases and disorders.

There is a need in the art for compounds that treat acomplement-mediated disease or disorder. There is also a need forcompounds that can detect or monitor such disease or disorder. Alsoneeded are methods to produce and use such compounds and compositionsthereof.

SUMMARY

The present disclosure provides antibodies that bind complement C1sprotein; and nucleic acid molecules that encode such antibodies. Thepresent disclosure also provides compositions comprising suchantibodies, and methods to produce and use such antibodies, nucleic acidmolecules, and compositions.

The present disclosure provides an isolated humanized monoclonalantibody that inhibits cleavage of complement component C4, where theantibody does not inhibit cleavage of complement component C2. In somecases, the antibody inhibits a component of the classical complementpathway; in some cases, the classical complement pathway component isC1s. In some instances, the antibody does not inhibit protease activityof C1s.

The present disclosure provides an isolated humanized monoclonalantibody that specifically binds an epitope within a region encompassingdomains IV and V of complement component is (C1s). In some cases, theantibody inhibits binding of C1s to complement component 4 (C4). In somecases, the antibody does not inhibit protease activity of C1s. In somecases, the epitope bound by an isolated humanized monoclonal antibody ofthe present disclosure is a conformational epitope.

The present disclosure provides an isolated humanized monoclonalantibody that binds complement component C1s in a C1 complex with highavidity.

The present disclosure provides an isolated humanized monoclonalantibody that is specific for complement component C1s and that inhibitscomplement-mediated cell lysis with an IC50 of less than 10×10⁻⁹ Mand/or inhibits C4 activation with an IC50 of less than 50×10⁻⁹ M.

In any of the embodiments of the present disclosure, the antibody cancomprise one or more of the complementarity determining regions (CDRs)of an antibody light chain variable region comprising amino acidsequence SEQ ID NO:7 or one or more of the CDRs of an antibody heavychain variable region comprising amino acid sequence SEQ ID NO:8.

In any of the embodiments of the present disclosure, the antibody cancomprise: a) a complementarity determining region (CDR) having an aminoacid sequence selected from the group consisting of SEQ ID NO:1, SEQ IDNO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, and SEQ ID NO:6; or b) aCDR having an amino acid sequence selected from the group consisting ofSEQ ID NO:32, SEQ ID NO:33, SEQ ID NO:3, SEQ ID NO:34, SEQ ID NO:35: andSEQ ID NO:36.

In any of the embodiments of the present disclosure, the antibody cancomprise: a) light chain CDRs of an antibody light chain variable regioncomprising amino acid sequence SEQ ID NO:7 or heavy chain CDRs of anantibody heavy chain variable region comprising amino acid sequence SEQID NO:8; or b) light chain CDRs of an antibody light chain variableregion comprising amino acid sequence SEQ ID NO:37 or heavy chain CDRsof an antibody heavy chain variable region comprising amino acidsequence SEQ ID NO:38.

In any of the embodiments of the present disclosure, the antibody cancomprise: a) light chain CDRs of an antibody light chain variable regioncomprising amino acid sequence SEQ ID NO:7 and heavy chain CDRs of anantibody heavy chain variable region comprising amino acid sequence SEQID NO:8; or b) light chain CDRs of an antibody light chain variableregion comprising amino acid sequence SEQ ID NO:37 and heavy chain CDRsof an antibody heavy chain variable region comprising amino acidsequence SEQ ID NO:38.

In any of the embodiments of the present disclosure, the antibody cancomprise heavy and light chain complementarity-determining regions(CDRs) having an amino acid sequence selected from: a) SEQ ID NO:1, SEQID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, and SEQ ID NO:6; and b)a CDR having an amino acid sequence selected from the group consistingof SEQ ID NO:32, SEQ ID NO:33, SEQ ID NO:3, SEQ ID NO:34, SEQ ID NO:35:and SEQ ID NO:36.

The present disclosure provides a humanized antibody that specificallybinds complement component 1s (C1s), wherein the antibody competes forbinding the epitope with an antibody that comprises one or more of theCDRs of an antibody light chain variable region comprising amino acidsequence SEQ ID NO:7 or one or more of the CDRs of an antibody heavychain variable region comprising amino acid sequence SEQ ID NO:8.

The present disclosure provides a humanized antibody that specificallybinds complement component 1s (C1s), wherein the antibody is selectedfrom the group consisting of: a) a humanized antibody that specificallybinds an epitope within the complement C1s protein, wherein the antibodycompetes for binding the epitope with an antibody that comprises a CDRhaving an amino acid sequence selected from the group consisting of SEQID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, and SEQ IDNO:6; and b) a humanized antibody that specifically binds an epitopewithin the complement C1s protein, wherein the antibody competes forbinding the epitope with an antibody that comprises a CDR having anamino acid sequence selected from the group consisting of SEQ ID NO:32,SEQ ID NO:33, SEQ ID NO:3, SEQ ID NO:34, SEQ ID NO:35, and SEQ ID NO:36.

The present disclosure provides a humanized antibody that binds acomplement C1s protein, wherein the antibody specifically binds anepitope within the complement C1s protein, wherein the antibody competesfor binding the epitope with an antibody that comprises: a) light chainCDRs of an antibody light chain variable region comprising amino acidsequence SEQ ID NO:7 or SEQ ID NO:37; or b) heavy chain CDRs of anantibody heavy chain variable region comprising amino acid sequence SEQID NO:8 or SEQ ID NO:38.

The present disclosure provides a humanized antibody that binds acomplement C1s protein, wherein the antibody specifically binds anepitope within the complement C1s protein, wherein the antibody competesfor binding the epitope with an antibody that comprises: a) light chainCDRs of an antibody light chain variable region comprising amino acidsequence SEQ ID NO:7 or SEQ ID NO:37; and b) heavy chain CDRs of anantibody heavy chain variable region comprising amino acid sequence SEQID NO:8 or SEQ ID NO:38. In some cases, the antibody competes forbinding the epitope with an antibody that comprises heavy and lightchain CDRs comprising: a) SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ IDNO:142, SEQ ID NO:5, and SEQ ID NO:6; or b) SEQ ID NO:32, SEQ ID NO:33,SEQ ID NO:3, SEQ ID NO:34, SEQ ID NO:35, and SEQ ID NO:36.

In any of the embodiments of the present disclosure, the antibody canbind a human complement C1s protein. In any of the embodiments of thepresent disclosure, the antibody can bind a rat complement C1s protein.In any of the embodiments of the present disclosure, the antibody canbind a monkey complement C1s protein. In any of the embodiments of thepresent disclosure, the antibody can bind a human complement C1sprotein, a rat complement C1s protein, and a monkey complement C1sprotein. In any of the embodiments of the present disclosure, theantibody can comprise a humanized light chain framework region. Forexample, the humanized light chain framework region can comprise 1, 2,3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18 of the aminoacid substitutions depicted in Table 8. In any of the embodiments of thepresent disclosure, the antibody can comprise a humanized heavy chainframework region. For example, the humanized heavy chain frameworkregion can comprise 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 of theamino acid substitutions depicted in Table 7. In any of the embodimentsof the present disclosure, the antibody can be an antigen bindingfragment that binds complement C1s protein. In any of the embodiments ofthe present disclosure, the antibody is selected from the groupconsisting of an Ig monomer, a Fab fragment, a F(ab′)₂ fragment, a Fdfragment, a scFv, a scAb, a dAb, a Fv, a single domain heavy chainantibody, and a single domain light chain antibody. In any of theembodiments of the present disclosure, the antibody is selected from thegroup consisting of a mono-specific antibody, a bi-specific antibody,and a multi-specific antibody. In any of the embodiments of the presentdisclosure, the antibody can comprise a light chain region and a heavychain region that are present in separate polypeptides. In any of theembodiments of the present disclosure, the antibody can comprise a lightchain region and a heavy chain region that are present in a singlepolypeptide. In any of the embodiments of the present disclosure, theantibody can comprise an Fc region. In any of the embodiments of thepresent disclosure, the light chain and heavy chain CDRs are selectedfrom the group consisting of: a) SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3,SEQ ID NO:4, SEQ ID NO:5, and SEQ ID NO:6; and b) SEQ ID NO:32, SEQ IDNO:33, SEQ ID NO:3, SEQ ID NO:34, SEQ ID NO:35, and SEQ ID NO:36.

The present disclosure provides an antibody that binds a complement C1sprotein, where the antibody comprises a complementarity-determiningregion (CDR) having an amino acid sequence selected from the groupconsisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ IDNO:5, and SEQ ID NO:6. In some embodiments, the antibody comprises alight chain variable region comprising amino acid sequences SEQ ID NO:1,SEQ ID NO:2, and SEQ ID NO:3. In some embodiments, the antibodycomprises a heavy chain variable region comprising amino acid sequencesSEQ ID NO:4, SEQ ID NO:5, and SEQ ID NO:6. In some embodiments, theantibody comprises a CDR-L1 having amino acid sequence SEQ ID NO:1, aCDR-L2 having amino acid sequence SEQ ID NO:2, a CDR-L3 having aminoacid sequence SEQ ID NO:3, a CDR-H1 having amino acid sequence SEQ IDNO:4, a CDR-H2 having amino acid sequence SEQ ID NO:5, and a CDR-H3having amino acid sequence SEQ ID NO:6.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a light chain variable region comprising an amino acidsequence that is 90% identical to amino acid sequence SEQ ID NO:7. Insome embodiments, an anti-C1s antibody of the present disclosurecomprises a heavy chain variable region comprising an amino acidsequence that is 90% identical to amino acid sequence SEQ ID NO:8. Insome embodiments, an anti-C1s antibody of the present disclosurecomprises a light chain variable region comprising amino acid sequenceSEQ ID NO:7. In some embodiments, an anti-C1s antibody of the presentdisclosure comprises a heavy chain variable region comprising amino acidsequence SEQ ID NO:8. In some embodiments, an anti-C1s antibody of thepresent disclosure comprises a light chain variable region comprising anamino acid sequence that is 90% identical to amino acid sequence SEQ IDNO:7 and a heavy chain variable region comprising an amino acid sequencethat is 90% identical to amino acid sequence SEQ ID NO:8. In someembodiments, an anti-C1s antibody of the present disclosure comprises alight chain variable region comprising amino acid sequence SEQ ID NO:7and a heavy chain variable region comprising amino acid sequence SEQ IDNO:8.

The present disclosure provides an antibody that binds a complement C1sprotein, wherein the antibody specifically binds an epitope within thecomplement C1s protein, wherein the antibody competes for binding theepitope with an antibody that comprises light chain CDRs of an antibodylight chain variable region comprising amino acid sequence SEQ ID NO:7and heavy chain CDRs of an antibody heavy chain variable regioncomprising amino acid sequence SEQ ID NO:8. In some embodiments, ananti-C1s antibody of the present disclosure comprises light chain CDRsof an antibody light chain variable region comprising amino acidsequence SEQ ID NO:7 and heavy chain CDRs of an antibody heavy chainvariable region comprising amino acid sequence SEQ ID NO:8.

In any of the above-noted embodiments, an anti-C1s antibody of thepresent disclosure binds a human complement C1s protein. In someembodiments, an anti-C1s antibody of the present disclosure binds a ratcomplement C1s protein. In some embodiments, an anti-C1s antibody of thepresent disclosure inhibits cleavage of at least one substrate cleavedby complement C1s protein. In some embodiments, the substrate isselected from the group consisting of complement C2 and complement C4.

In any of the above-noted embodiments, an anti-C1s antibody of thepresent disclosure can comprise a humanized light chain frameworkregion. In any of the above-noted embodiments, an anti-C1s antibody ofthe present disclosure can comprise a humanized heavy chain frameworkregion.

In any of the above-noted embodiments, an anti-C1s antibody of thepresent disclosure can be an Ig monomer or an antigen-binding fragmentthereof that binds complement C1s protein. In any of the above-notedembodiments, an anti-C1s antibody of the present disclosure can be anantigen-binding fragment that binds complement C1s protein. In any ofthe above-noted embodiments, an anti-C1s antibody of the presentdisclosure is selected from the group consisting of an Ig monomer, a Fabfragment, a F(ab′)₂ fragment, a Fd fragment, a scFv, a scAb, a dAb, aFv, a single domain heavy chain antibody, and a single domain lightchain antibody. In any of the above-noted embodiments, an anti-C1santibody of the present disclosure is selected from the group consistingof a mono-specific antibody, a bi-specific antibody, and amulti-specific antibody.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a light chain region and a heavy chain region that are presentin separate polypeptides. In some embodiments, an anti-C1s antibody ofthe present disclosure comprises a light chain region and a heavy chainregion that are present in a single polypeptide. In some embodiments, ananti-C1s antibody of the present disclosure comprises a Fc region.

The present disclosure provides an antibody that competes for bindingthe epitope bound by antibody IPN003 (also referred to herein as“IPN-M34” or “M34” or “TNT003”). The present disclosure provides anantibody comprising a variable domain of antibody IPN003. The presentdisclosure provides antibody IPN003.

The present disclosure provides an anti-C1s antibody produced by amethod comprising recombinant production.

The present disclosure provides an antibody that binds a complement C1sprotein, wherein the antibody is encapsulated in a liposome.

The present disclosure provides an antibody that binds a complement C1sprotein, wherein the antibody comprises a covalently linked non-peptidesynthetic polymer. In some embodiments, the synthetic polymer is apoly(ethylene glycol) polymer.

The present disclosure provides an antibody that binds a complement C1sprotein, wherein the antibody is formulated with an agent thatfacilitates crossing the blood-brain barrier.

The present disclosure provides an antibody that binds a complement C1sprotein, wherein the antibody is fused, directly or through a linker, toa compound that promotes the crossing of the blood-brain barrier,wherein the compound is selected from the group consisting of a carriermolecule, a peptide, or a protein.

The present disclosure provides a nucleic acid molecule that encodes ananti-C1s antibody of any of the embodiments disclosed herein. In someembodiments, the present disclosure provides a recombinant vectorcomprising such a nucleic acid molecule. In some embodiments, thepresent disclosure provides a recombinant molecule comprising such anucleic acid molecule. In some embodiments, the present disclosureprovides a recombinant cell comprising such a recombinant molecule.

The present disclosure provides a pharmaceutical composition comprisingan anti-C1s antibody of any of the embodiments disclosed herein and apharmaceutically acceptable excipient. Some embodiments include asterile container comprising such a pharmaceutical composition. In someembodiments, the container is selected from the group consisting of abottle and a syringe.

The present disclosure provides a method to treat an individual having acomplement-mediated disease or disorder, the method comprisingadministering to the individual an anti-C1s antibody of any of theembodiments disclosed herein or a pharmaceutical composition thereof. Insome embodiments, the individual is a mammal. In some embodiments, theindividual is a human. In some embodiments, the administering isintravenous. In some embodiments, the administering is intrathecal. Insome embodiments, the administering results in an outcome selected fromthe group consisting of: (a) a reduction in complement activation; (b)an improvement in cognitive function; (c) a reduction in neuron loss;(d) a reduction in phospho-Tau levels in neurons; (e) a reduction inglial cell activation; (f) a reduction in lymphocyte infiltration; (g) areduction in macrophage infiltration; (h) a reduction in antibodydeposition; (i) a reduction in glial cell loss; (j) a reduction inoligodendrocyte loss; (k) a reduction in dendritic cell infiltration;(l) a reduction in neutrophil infiltration; (m) a reduction in red bloodcell lysis; (n) a reduction in red blood cell phagocytosis; (O) areduction in platelet phagocytosis; (p) a reduction in platelet lysis;(q) an improvement in transplant graft survival; (r) a reduction inmacrophage mediated phagocytosis; (s) an improvement in vision; (t) animprovement in motor control; (u) an improvement in thrombus formation;(v) an improvement in clotting; (w) an improvement in kidney function;(x) a reduction in antibody mediated complement activation; (y) areduction in autoantibody mediated complement activation; (z) animprovement in anemia; (aa) a reduction in demyelination; (ab) areduction in eosinophilia; (ac) a reduction in C3 deposition on redblood cells (e.g., a reduction of deposition of C3b, iC3b, etc., onRBCs); (ad) a reduction in C3 deposition on platelets (e.g., a reductionof deposition of C3b, iC3b, etc., on platelets); (ae) reduction inanaphylatoxin (e.g., C3a, C4a, C5a) production; (af) a reduction inautoantibody mediated blister formation; (ag) a reduction inautoantibody induced pruritis; (ah) a reduction in autoantibody inducederythematosus; (ai) a reduction in autoantibody mediated skin erosion;(aj) a reduction in red blood cell destruction due to transfusionreactions; (ak) a reduction in red blood cell lysis due toalloantibodies; (al) a reduction in hemolysis due to transfusionreactions; (am) a reduction in allo-antibody mediated platelet lysis;(an) a reduction in platelet lysis due to transfusion reactions; (ao) areduction in mast cell activation; (ap) a reduction in mast cellhistamine release; (aq) a reduction in vascular permeability; (ar) areduction in edema; (as) a reduction in complement deposition ontransplant graft endothelium; (at) a reduction of anaphylatoxingeneration in transplant graft endothelium; (au) a reduction in theseparation of the dermal-epidermal junction; (av) a reduction in thegeneration of anaphylatoxins in the dermal-epidermal junction; (aw) areduction in alloantibody mediated complement activation in transplantgraft endothelium; (ax) a reduction in antibody mediated loss of theneuromuscular junction; (ay) a reduction in complement activation at theneuromuscular junction; (az) a reduction in anaphylatoxin generation atthe neuromuscular junction; (ba) a reduction in complement deposition atthe neuromuscular junction; (bb) a reduction in paralysis; (bc) areduction in numbness; (bd) increased bladder control; (be) increasedbowel control; (bf) a reduction in mortality associated withautoantibodies; and (bg) a reduction in morbidity associated withautoantibodies. In some embodiments, the reduction in glial cellactivation comprises reduction in astrocyte activation or reduction inmicroglia activation.

The present disclosure provides a method to inhibit complementactivation in an individual having a complement-mediated disease ordisorder, the method comprising administering to the individual ananti-C1s antibody of any of the embodiments disclosed herein or apharmaceutical composition thereof. In some embodiments, the individualis a mammal. In some embodiments, the individual is a human. In someembodiments, the administering is intravenous. In some embodiments, theadministering is intrathecal. In some embodiments, the administering issubcutaneous. In some embodiments, the administering results in anoutcome selected from the group consisting of: (a) a reduction incomplement activation; (b) an improvement in cognitive function; (c) areduction in neuron loss; (d) a reduction in phospho-Tau levels inneurons; (e) a reduction in glial cell activation; (f) a reduction inlymphocyte infiltration; (g) a reduction in macrophage infiltration; (h)a reduction in antibody deposition; (i) a reduction in glial cell loss;(j) a reduction in oligodendrocyte loss; (k) a reduction in dendriticcell infiltration; (l) a reduction in neutrophil infiltration; (m) areduction in red blood cell lysis; (n) a reduction in red blood cellphagocytosis; (o) a reduction in platelet phagocytosis; (p) a reductionin platelet lysis; (q) an improvement in transplant graft survival; (r)a reduction in macrophage mediated phagocytosis; (s) an improvement invision; (t) an improvement in motor control; (u) an improvement inthrombus formation; (v) an improvement in clotting; (w) an improvementin kidney function; (x) a reduction in antibody mediated complementactivation; (y) a reduction in autoantibody mediated complementactivation; (z) an improvement in anemia; (aa) a reduction indemyelination; (ab) a reduction in eosinophilia; (ac) a reduction in C3deposition on red blood cells (e.g., a reduction of deposition of C3b,iC3b, etc., on RBCs); (ad) a reduction in C3 deposition on platelets(e.g., a reduction of deposition of C3b, iC3b, etc., on platelets); (ae)reduction in anaphylatoxin production; (af) a reduction in autoantibodymediated blister formation; (ag) a reduction in autoantibody inducedpruritis; (ah) a reduction in autoantibody induced erythematosus; (ai) areduction in autoantibody mediated skin erosion; (aj) a reduction in redblood cell destruction due to transfusion reactions; (ak) a reduction inred blood cell lysis due to alloantibodies; (al) a reduction inhemolysis due to transfusion reactions; (am) a reduction inallo-antibody mediated platelet lysis; (an) a reduction in plateletlysis due to transfusion reactions; (ao) a reduction in mast cellactivation; (ap) a reduction in mast cell histamine release; (aq) areduction in vascular permeability; (ar) a reduction in edema; (as) areduction in complement deposition on transplant graft endothelium; (at)a reduction of anaphylatoxin generation in transplant graft endothelium;(au) a reduction in the separation of the dermal-epidermal junction;(av) a reduction in the generation of anaphylatoxins in thedermal-epidermal junction; (aw) a reduction in alloantibody mediatedcomplement activation in transplant graft endothelium; (ax) a reductionin antibody mediated loss of the neuromuscular junction; (ay) areduction in complement activation at the neuromuscular junction; (az) areduction in anaphylatoxin generation at the neuromuscular junction;(ba) a reduction in complement deposition at the neuromuscular junction;(bb) a reduction in paralysis; (bc) a reduction in numbness; (bd)increased bladder control; (be) increased bowel control; (bf) areduction in mortality associated with autoantibodies; and (bg) areduction in morbidity associated with autoantibodies. In someembodiments, the reduction in glial cell activation comprises reductionin astrocyte activation or reduction in microglia activation.

The present disclosure provides use of an anti-C1s antibody of any ofthe embodiments or a pharmaceutical composition thereof to treat anindividual having a complement-mediated disease or disorder.

The present disclosure provides use of an anti-C1s antibody of any ofthe embodiments in the manufacture of a medicament for the treatment ofan individual having a complement-mediated disease or disorder.

The present disclosure provides use of an anti-C1s antibody of any ofthe embodiments or a pharmaceutical composition thereof for inhibitingcomplement C1s activity, where “inhibiting complement C1s activity”includes inhibiting complement activation, e.g., inhibiting productionof C4b2a (i.e., complement C4b and C2a complex; also known as “C3convertase”). In some embodiments, the present disclosure provides useof an anti-C1s antibody of any of the embodiments or a pharmaceuticalcomposition thereof for inhibiting complement activation in anindividual having a complement-mediated disease or disorder.

The present disclosure provides use of an anti-C1s antibody of any ofthe embodiments or a pharmaceutical composition thereof in themanufacture of a medicament for inhibiting complement activation. Insome embodiments, the present disclosure provides use of an anti-C1santibody of any of the embodiments or a pharmaceutical compositionthereof in the manufacture of a medicament for inhibiting complementactivation in an individual having a complement-mediated disease ordisorder.

The present disclosure provides an anti-C1s antibody of any of theembodiments or a pharmaceutical composition thereof for use in medicaltherapy.

The present disclosure provides an anti-C1s antibody of any of theembodiments or a pharmaceutical composition thereof for treating anindividual having a complement-mediated disease or disorder.

The present disclosure provides an anti-C1s antibody of any of theembodiments or a pharmaceutical composition thereof for inhibitingcomplement activation. The present disclosure provides an anti-C1santibody of any of the embodiments or a pharmaceutical compositionthereof for inhibiting complement activation in an individual having acomplement-mediated disease or disorder.

The present disclosure provides a method to diagnose acomplement-mediated disease or disorder in an individual, the methodcomprising: (a) determining the amount of a complement C1s protein in abiological sample obtained from the individual, wherein the step ofdetermining comprises: (i) contacting the biological sample with ananti-C1s antibody of any of the embodiments; and (ii) quantitatingbinding of the antibody to complement C1s protein present in thebiological sample; and (b) comparing the amount of the complement C1sprotein in the biological sample to a normal control value thatindicates the amount of complement C1s protein in a normal controlindividual, wherein a significant difference between the amount of C1sprotein in the biological sample and the normal control value indicatesthat the individual has a complement-mediated disease or disorder. Insome embodiments, the biological sample is selected from the groupconsisting of blood, serum, plasma, urine, saliva, cerebrospinal fluid,interstitial fluid, ocular fluid, synovial fluid, solid tissue sample,tissue culture sample, and cellular sample.

The present disclosure provides a method to monitor progression of acomplement-mediated disease or disorder in an individual, the methodcomprising: (a) determining a first amount of a complement C1s proteinin a biological sample obtained from the individual at a first timepoint; (b) determining a second amount of complement a C1s protein in abiological sample obtained from the individual at a second time point;and (c) comparing the second amount of complement C1s protein with thefirst amount of complement C1s protein. The steps of determiningcomprise: (i) contacting the biological sample with an anti-C1s antibodyof any of the embodiments; and (ii) quantitating binding of the antibodyto complement C1s protein present in the biological sample. In someembodiments, the first time point is a time point before initiation of atreatment regimen, and the second time point is a time point afterinitiation of a treatment regimen. In some embodiments, the biologicalsample is selected from the group consisting of blood, serum, plasma,urine, saliva, cerebrospinal fluid, interstitial fluid, ocular fluid,synovial fluid, solid tissue sample, tissue culture sample, and cellularsample.

The present disclosure provides an in vitro method to detect complementC1s protein in a biological sample obtained from an individual, themethod comprising: (a) contacting the biological sample with an anti-C1santibody of any of the embodiments; and (b) detecting binding of theantibody to complement C1s protein present in the biological sample. Insome embodiments, the biological sample is selected from the groupconsisting of blood, serum, plasma, urine, saliva, cerebrospinal fluid,interstitial fluid, ocular fluid, synovial fluid, solid tissue sample,tissue culture sample, and cellular sample. In some embodiments, themethod is quantitative.

The present disclosure provides a method to detect complement C1sprotein in a living individual in vivo, the method comprising: (a)administering to the individual an anti-C1s antibody of any of theembodiments; and (b) detecting binding of the antibody to complement C1sprotein in the individual using an imaging method. In some embodiments,the binding is detected in the individual at a site altered by acomplement-mediated disease or disorder. In some embodiments, thebinding is detected in the brain of the individual. In some of theembodiments, the antibody comprises a contrast agent suitable for use inthe imaging method. In some embodiments, the imaging method is selectedfrom the group consisting of magnetic resonance imaging, positronemission tomography, and IVIS instrumentation. In some embodiments, themethod is quantitative.

In some embodiments, the biological sample is selected from the groupconsisting of blood, serum, plasma, urine, saliva, cerebrospinal fluid,interstitial fluid, ocular fluid, synovial fluid, solid tissue sample,tissue culture sample, and cellular sample.

In some embodiments, the methods of the present disclosure provide thatthe individual is suspected of having a complement-mediated disease ordisorder, has been diagnosed as having a complement-mediated disease ordisorder, or has a genetic predisposition to developing acomplement-mediated disease or disorder.

The present disclosure provides a composition comprising: (a) ananti-C1s antibody of any of the embodiments; and (b) a solutioncomprising one or more agents that maintain an organ or a tissueintended for transplantation into a recipient individual. In someembodiments, the solution is an organ preservation solution or a tissuepreservation solution. In some embodiments, the solution is an organperfusion solution or a tissue perfusion solution. In some embodiments,the solution comprises: i) a salt; ii) an agent that reduces edema; iii)an oxygen free-radical scavenger; and iii) an energy supply systemcomponent. In some embodiments, the composition comprises potassiumlactobionate, KH₂PO₄, MgSO₄, raffinose, adenosine, glutathione,allopurinol, and hydroxyethyl starch.

The present disclosure provides an organ or tissue preservation solutioncomprising an anti-C1s antibody of any of the embodiments or apharmaceutical composition thereof.

The present disclosure provides an organ or tissue perfusion solutioncomprising an anti-Cls antibody of any of the embodiments or apharmaceutical composition thereof.

The present disclosure provides a method for maintaining an organ ortissue for transplant, the method comprising contacting the organ or thetissue with a composition comprising: (a) an anti-C1s antibody of any ofthe embodiments; and (b) an organ or tissue preservation solution of anyof the embodiments or an organ or tissue perfusion solution of any ofthe embodiments.

The present disclosure provides an isolated organ or tissue maintainedin a composition comprising: (a) an anti-C1s antibody of any of theembodiments; and (b) an organ or tissue preservation solution of any ofthe embodiments or an organ or tissue perfusion solution of any of theembodiments. In some embodiments, the organ is selected from the groupconsisting of an eye, a heart, an intestine, a kidney, a liver, a lung,a pancreas, a stomach, and a thymus. In some embodiments, the tissue isselected from the group consisting of bone, bone marrow, cornea, heartvalve, islet of Langerhans, tendon, skin, and vein.

The present disclosure provides an in vitro method for inhibitingcomplement activation in an organ or a tissue, the method comprisingcontacting the organ or the tissue with an anti-C1s antibody of any ofthe embodiments, a solution comprising an anti-C1s antibody of any ofthe embodiments, or a pharmaceutical composition comprising an anti-C1santibody of any of the embodiments.

Certain aspects of the invention are defined in the following numberedparagraphs (0056-0076).

An antibody that binds a complement C1s protein, wherein the antibodycomprises a complementarity-determining region (CDR) having an aminoacid sequence selected from the group consisting of SEQ ID NO:1, SEQ IDNO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, and SEQ ID NO:6.

The antibody of paragraph 0056, wherein the antibody comprises a lightchain variable region comprising amino acid sequences SEQ ID NO:1, SEQID NO:2, and SEQ ID NO:3. The antibody of paragraph 0056, wherein theantibody comprises a heavy chain variable region comprising amino acidsequences SEQ ID NO:4, SEQ ID NO:5, and SEQ ID NO:6.

The antibody of paragraph 0056, wherein the antibody comprises a CDR-L1having amino acid sequence SEQ ID NO:1, a CDR-L2 having amino acidsequence SEQ ID NO:2, a CDR-L3 having amino acid sequence SEQ ID NO:3, aCDR-H1 having amino acid sequence SEQ ID NO:4, a CDR-H2 having aminoacid sequence SEQ ID NO:5, and a CDR-H3 having amino acid sequence SEQID NO:6.

The antibody of paragraph 0056, wherein the antibody comprises a lightchain variable region comprising an amino acid sequence that is 90%identical to amino acid sequence SEQ ID NO:7. The antibody of paragraph0056, wherein the antibody comprises a heavy chain variable regioncomprising an amino acid sequence that is 90% identical to amino acidsequence SEQ ID NO:8. The antibody of paragraph 0056, wherein theantibody comprises a light chain variable region comprising amino acidsequence SEQ ID NO:7. The antibody of paragraph 0056, wherein theantibody comprises a heavy chain variable region comprising amino acidsequence SEQ ID NO:8.

The antibody of paragraph 0056, wherein the antibody comprises a lightchain variable region comprising an amino acid sequence that is 90%identical to amino acid sequence SEQ ID NO:7 and a heavy chain variableregion comprising an amino acid sequence that is 90% identical to aminoacid sequence SEQ ID NO:8. The antibody of paragraph 0056, wherein theantibody comprises a light chain variable region comprising amino acidsequence SEQ ID NO:7 and a heavy chain variable region comprising aminoacid sequence SEQ ID NO:8.

An antibody that binds a complement C1s protein, wherein the antibodyspecifically binds an epitope within the complement C1s protein, whereinthe antibody competes for binding the epitope with an antibody thatcomprises light chain CDRs of an antibody light chain variable regioncomprising amino acid sequence SEQ ID NO:7 and heavy chain CDRs of anantibody heavy chain variable region comprising amino acid sequence SEQID NO:8.

The antibody of paragraph 0061, wherein the antibody comprises lightchain CDRs of an antibody light chain variable region comprising aminoacid sequence SEQ ID NO:7 and heavy chain CDRs of an antibody heavychain variable region comprising amino acid sequence SEQ ID NO:8.

The antibody of any one of paragraphs 0056-0062, wherein the antibodybinds a human complement C1s protein. The antibody of any one ofparagraphs 0056-0062, wherein the antibody binds a rat complement C1sprotein or a monkey complement C1s protein.

The antibody of any one of paragraphs 0056-0063, wherein the antibodyinhibits cleavage of at least one substrate cleaved by complement C1sprotein.

The antibody of paragraph 0064, wherein the substrate is selected fromthe group consisting of complement C2 and complement C4.

The antibody of any one of paragraphs 0056-0065, wherein the antibodycomprises a humanized light chain framework region. The antibody of anyone of paragraphs 0056-0065, wherein the antibody comprises a humanizedheavy chain framework region.

The antibody of any one of paragraphs 0056-0066, wherein the antibody isselected from the group consisting of an Ig monomer and anantigen-binding fragment thereof that binds complement C1s protein.

The antibody of any one of paragraphs 0056-0066, wherein the antibody isan antigen binding fragment that binds complement C1s protein.

The antibody of any one of paragraphs 0056-0066, wherein the antibody isselected from the group consisting of an Ig monomer, a Fab fragment, aF(ab′)₂ fragment, a Fd fragment, a scFv, a scAb, a dAb, a Fv, a singledomain heavy chain antibody, and a single domain light chain antibody.

The antibody of any one of paragraphs 0056-0066, wherein the antibody isselected from the group consisting of a mono-specific antibody, abi-specific antibody, and a multi-specific antibody. The antibody of anyone of paragraphs 0056-0066, wherein the antibody comprises a lightchain region and a heavy chain region that are present in separatepolypeptides. The antibody of any one of paragraphs 0056-0066, whereinthe antibody comprises a light chain region and a heavy chain regionthat are present in a single polypeptide.

The antibody of any one of paragraphs 0056-0066 and 0070, wherein theantibody comprises a Fc region.

The antibody of any one of paragraphs 0056-0071, wherein the antibody isencapsulated in a liposome.

The antibody of any one of paragraphs 0056-0071, wherein the antibodycomprises a covalently linked non-peptide synthetic polymer.

The antibody of paragraph 0073, where in the synthetic polymer is apoly(ethylene glycol) polymer.

The antibody of any one of paragraphs 0056-0071, wherein the antibody isformulated with an agent that facilitates crossing the blood-brainbarrier.

The antibody of any one of paragraphs 0056-0071, wherein the antibody isfused, directly or through a linker, to a compound that promotes thecrossing of the blood-brain barrier, wherein the compound is selectedfrom the group consisting of a carrier molecule, a peptide, or aprotein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts the amino acid sequence of Homo sapiens complement C1sprotein (SEQ ID NO:9).

FIG. 2 provides Table 2.

FIG. 3 depicts competition by IPN003 (M34) for binding of M81 to humanC1s.

FIG. 4 depicts IPN003 inhibition of C1s-mediated activation of humancomplement protein C4.

FIG. 5 depicts the effect of IPN003 on activation of the intactclassical complement cascade using a standard hemolysis assay.

FIGS. 6 and 7 depict inhibition by IPN003 of complement in serum fromtwo species of monkey.

FIG. 8 depicts the specificity of IPN003 for C1s.

FIG. 9 provides Table 4.

FIG. 10 depicts binding of IPN003 and M81 to rat C1s.

FIG. 11 depicts IPN003 inhibition of rat C1s-mediated cleavage of humanC4.

FIG. 12 depicts IPN003 inhibition of rat C1s-mediated cleavage of humanC4 and IPN003 inhibition of human C1s-mediated cleavage of human C4.

FIG. 13 depicts the effect of IPN003 on patient serum-mediated hemolysisof human red blood cells.

FIG. 14 depicts the effect of IPN003 on patient serum-mediated C3bdeposition on human red blood cells.

FIG. 15 provides amino acid sequences of IPN003 VL and VH regions,IPN003 VL CDRs, and IPN003 VH CDRs.

FIG. 16 depicts an amino acid sequence of humanized IPN003 VH variant 1;and a nucleotide sequence (SEQ ID NO: 46) encoding the amino acidsequence.

FIG. 17 depicts an amino acid sequence of humanized IPN003 VH variant 2;and a nucleotide sequence (SEQ ID NO: 47) encoding the amino acidsequence.

FIG. 18 depicts an amino acid sequence of humanized IPN003 VH variant 3;and a nucleotide sequence (SEQ ID NO: 48) encoding the amino acidsequence.

FIG. 19 depicts an amino acid sequence of humanized IPN003 VH variant 4;and a nucleotide sequence (SEQ ID NO: 49) encoding the amino acidsequence.

FIG. 20 depicts an amino acid sequence of humanized IPN003 Vκ variant 1;and a nucleotide sequence (SEQ ID NO: 50) encoding the amino acidsequence.

FIG. 21 depicts an amino acid sequence of humanized IPN003 Vκ variant 2;and a nucleotide sequence (SEQ ID NO: 51) encoding the amino acidsequence.

FIG. 22 depicts an amino acid sequence of humanized IPN003 Vκ variant 3;and a nucleotide sequence (SEQ ID NO: 52) encoding the amino acidsequence.

FIG. 23 provides Table 7, which shows the amino acid differences betweenparental IPN003 VH and exemplary VH variants; and Table 8, which showsthe amino acid differences between parental IPN003 VL and exemplary VLvariants.

FIG. 24 provides Table 9 and 10, which shows binding properties ofhumanized IPN003 variants to activated C1s and to pro-C1s.

FIG. 25 depicts the IC₅₀ of humanized variants of IPN003 for competingwith IPN003 for binding to C1s.

FIG. 26 depicts inhibition of the complement classical pathway byhumanized variants of IPN003.

FIGS. 27A and 27B depict the effects of 3 humanized IPN003 variants onactivation of the classical complement pathway (FIG. 27A) and thealternative complement pathway (FIG. 27B).

FIG. 28 depicts the effect of humanized IPN003 variants oncomplement-mediated hemolysis and on C3b deposition onantibody-sensitized red blood cells (RBCs).

FIG. 29 depicts inhibition of cold agglutinin disease (CAD) patientplasma-mediated hemolysis by IPN003 or a humanized variant of IPN003(hu-IPN003).

FIG. 30 depicts inhibition of anaphylatoxin production by IPN003 orhu-IPN003.

FIG. 31 depicts inhibition of CAD patient plasma-mediated C3b depositionon human RBCs by IPN003.

FIG. 32 depicts concentration-dependent inhibition of CAD patientplasma-mediated C3b deposition on human RBCs by IPN003.

FIGS. 33A and 33B depict proliferation responses to a humanized variantof IPN003 (FIG. 33A) and to a chimeric anti-C1s antibody (FIG. 33B).

FIG. 34 depicts the effect of TNT003 on complement-dependent hemolysismediated by autoantibodies present in plasma of patients with coldagglutinin disease (CAD).

FIG. 35 depicts the effect of TNT003 on complement-dependent C3bdeposition mediated by autoantibodies present in plasma of patients withCAD.

FIG. 36 depicts the effect of TNT003 on complement-dependentphagocytosis mediated by autoantibodies present in plasma of patientswith CAD.

FIGS. 37A-C depict the effect of TNT003 on complement-dependent C3a, C4aand C5a generation mediated by autoantibodies present in plasma ofpatients with CAD.

FIGS. 38A and 38B depict the ex vivo activity of TNT003 on hemolysis andC3b deposition following administration to non-human primates.

FIG. 39 depicts the in vivo effect of TNT003 on C4a generation followingadministration to non-human primates.

FIG. 40 depicts binding of TNT003 to human C1s fragments.

FIG. 41 depicts the effect of mutation of D343 and D357 on inhibition ofC1s activity by TNT003.

FIG. 42 depicts inhibition of human C1s activity by TNT003.

FIGS. 43A and 43B depict TNT003 binding to C1s present in a C1 complex.

FIG. 44 depicts inhibition of human C1s by TNT003 and fragments ofTNT003

FIG. 45 depicts binding of TNT003 to human C1s under non-reducingconditions.

FIG. 46 depicts inhibition of activation of complement C4, but notcomplement C2, by TNT003.

FIG. 47 depicts C1s levels in plasma samples from healthy volunteers andfrom CAD patients.

DEFINITIONS

The terms “antibodies” and “immunoglobulin” include antibodies orimmunoglobulins of any isotype, fragments of antibodies that retainspecific binding to antigen, including, but not limited to, Fab, Fv,scFv, and Fd fragments, chimeric antibodies, humanized antibodies,single-chain antibodies (scAb), single domain antibodies (dAb), singledomain heavy chain antibodies, a single domain light chain antibodies,bi-specific antibodies, multi-specific antibodies, and fusion proteinscomprising an antigen-binding (also referred to herein as antigenbinding) portion of an antibody and a non-antibody protein. Theantibodies can be detectably labeled, e.g., with a radioisotope, anenzyme that generates a detectable product, a fluorescent protein, andthe like. The antibodies can be further conjugated to other moieties,such as members of specific binding pairs, e.g., biotin (member ofbiotin-avidin specific binding pair), and the like. The antibodies canalso be bound to a solid support, including, but not limited to,polystyrene plates or beads, and the like. Also encompassed by the termare Fab′, Fv, F(ab′)₂, and or other antibody fragments that retainspecific binding to antigen, and monoclonal antibodies. As used herein,a monoclonal antibody is an antibody produced by a group of identicalcells, all of which were produced from a single cell by repetitivecellular replication. That is, the clone of cells only produces a singleantibody species. While a monoclonal antibody can be produced usinghybridoma production technology, other production methods known to thoseskilled in the art can also be used (e.g., antibodies derived fromantibody phage display libraries). An antibody can be monovalent orbivalent. An antibody can be an Ig monomer, which is a “Y-shaped”molecule that consists of four polypeptide chains: two heavy chains andtwo light chains connected by disulfide bonds.

The term “humanized immunoglobulin” as used herein refers to animmunoglobulin comprising portions of immunoglobulins of differentorigin, wherein at least one portion comprises amino acid sequences ofhuman origin. For example, the humanized antibody can comprise portionsderived from an immunoglobulin of nonhuman origin with the requisitespecificity, such as a mouse, and from immunoglobulin sequences of humanorigin (e.g., chimeric immunoglobulin), joined together chemically byconventional techniques (e.g., synthetic) or prepared as a contiguouspolypeptide using genetic engineering techniques (e.g., DNA encoding theprotein portions of the chimeric antibody can be expressed to produce acontiguous polypeptide chain). Another example of a humanizedimmunoglobulin is an immunoglobulin containing one or moreimmunoglobulin chains comprising a CDR derived from an antibody ofnonhuman origin and a framework region derived from a light and/or heavychain of human origin (e.g., CDR-grafted antibodies with or withoutframework changes). Chimeric or CDR-grafted single chain antibodies arealso encompassed by the term humanized immunoglobulin. See, e.g.,Cabilly et al., U.S. Pat. No. 4,816,567; Cabilly et al., European PatentNo. 0,125,023 B1; Boss et al., U.S. Pat. No. 4,816,397; Boss et al.,European Patent No. 0,120,694 B1; Neuberger, M. S. et al., WO 86/01533;Neuberger, M. S. et al., European Patent No. 0,194,276 B1; Winter, U.S.Pat. No. 5,225,539; Winter, European Patent No. 0,239,400 B1; Padlan, E.A. et al., European Patent Application No. 0,519,596 A1. See also,Ladner et al., U.S. Pat. No. 4,946,778; Huston, U.S. Pat. No. 5,476,786;and Bird, R. E. et al., Science, 242: 423-426 (1988)), regarding singlechain antibodies.

For example, humanized immunoglobulins can be produced using syntheticand/or recombinant nucleic acids to prepare genes (e.g., cDNA) encodingthe desired humanized chain. For example, nucleic acid (e.g., DNA)sequences coding for humanized variable regions can be constructed usingPCR mutagenesis methods to alter DNA sequences encoding a human orhumanized chain, such as a DNA template from a previously humanizedvariable region (see e.g., Kamman, M., et al., Nucl. Acids Res., 17:5404 (1989)); Sato, K., et al., Cancer Research, 53: 851-856 (1993);Daugherty, B. L. et al., Nucleic Acids Res., 19(9): 2471-2476 (1991);and Lewis, A. P. and J. S. Crowe, Gene, 101: 297-302 (1991)). Usingthese or other suitable methods, variants can also be readily produced.For example, cloned variable regions can be mutagenized, and sequencesencoding variants with the desired specificity can be selected (e.g.,from a phage library; see e.g., Krebber et al., U.S. Pat. No. 5,514,548;Hoogenboom et al., WO 93/06213, published Apr. 1, 1993)).

“Antibody fragments” comprise a portion of an intact antibody, forexample, the antigen binding or variable region of the intact antibody.Examples of antibody fragments include Fab, Fab′, F(ab′)₂, and Fvfragments; diabodies; linear antibodies (Zapata et al., Protein Eng.8(10): 1057-1062 (1995)); domain antibodies (dAb; Holt et al. (2003)Trends Biotechnol. 21:484); single-chain antibody molecules; andmulti-specific antibodies formed from antibody fragments. Papaindigestion of antibodies produces two identical antigen-bindingfragments, called “Fab” fragments, each with a single antigen-bindingsite, and a residual “Fc” fragment, a designation reflecting the abilityto crystallize readily. Pepsin treatment yields an F(ab′)₂ fragment thathas two antigen combining sites and is still capable of cross-linkingantigen.

“Fv” is the minimum antibody fragment that contains a completeantigen-recognition and -binding site. This region consists of a dimerof one heavy- and one light-chain variable domain in tight, non-covalentassociation. It is in this configuration that the three CDRS of eachvariable domain interact to define an antigen-binding site on thesurface of the V_(H)-V_(L) dimer. Collectively, the six CDRs conferantigen-binding specificity to the antibody. However, even a singlevariable domain (or half of an Fv comprising only three CDRs specificfor an antigen) has the ability to recognize and bind antigen, althoughat a lower affinity than the entire binding site.

The “Fab” fragment also contains the constant domain of the light chainand the first constant domain (CH₁) of the heavy chain. Fab fragmentsdiffer from Fab′ fragments by the addition of a few residues at thecarboxyl terminus of the heavy chain CH₁ domain including one or morecysteines from the antibody hinge region. Fab′-SH is the designationherein for Fab′ in which the cysteine residue(s) of the constant domainsbear a free thiol group. F(ab′)₂ antibody fragments originally wereproduced as pairs of Fab′ fragments which have hinge cysteines betweenthem. Other chemical couplings of antibody fragments are also known.

The “light chains” of antibodies (immunoglobulins) from any vertebratespecies can be assigned to one of two clearly distinct types, calledkappa and lambda, based on the amino acid sequences of their constantdomains. Depending on the amino acid sequence of the constant domain oftheir heavy chains, immunoglobulins can be assigned to differentclasses. There are five major classes of immunoglobulins: IgA, IgD, IgE,IgG, and IgM, and several of these classes can be further divided intosubclasses (isotypes), e.g., IgG1, IgG2, IgG3, IgG4, IgA, and IgA2. Thesubclasses can be further divided into types, e.g., IgG2a and IgG2b.

“Single-chain Fv” or “sFv” or “scFv” antibody fragments comprise theV_(H) and V_(L) domains of antibody, wherein these domains are presentin a single polypeptide chain. In some embodiments, the Fv polypeptidefurther comprises a polypeptide linker between the V_(H) and V_(L)domains, which enables the sFv to form the desired structure for antigenbinding. For a review of sFv, see Pluckthun in The Pharmacology ofMonoclonal Antibodies, vol. 113, Rosenburg and Moore eds.,Springer-Verlag, New York, pp. 269-315 (1994).

The term “diabodies” refers to small antibody fragments with twoantigen-binding sites, which fragments comprise a heavy-chain variabledomain (V_(H)) connected to a light-chain variable domain (V_(L)) in thesame polypeptide chain (V_(H)-V_(L)). By using a linker that is tooshort to allow pairing between the two domains on the same chain, thedomains are forced to pair with the complementary domains of anotherchain and create two antigen-binding sites. Diabodies are described morefully in, for example, EP 404,097; WO 93/11161; and Hollinger et al.(1993) Proc. Natl. Acad. Sci. USA 90:6444-6448.

As used herein, the term “affinity” refers to the equilibrium constantfor the reversible binding of two agents (e.g., an antibody and anantigen) and is expressed as a dissociation constant (K_(D)). Affinitycan be at least 1-fold greater, at least 2-fold greater, at least 3-foldgreater, at least 4-fold greater, at least 5-fold greater, at least6-fold greater, at least 7-fold greater, at least 8-fold greater, atleast 9-fold greater, at least 10-fold greater, at least 20-foldgreater, at least 30-fold greater, at least 40-fold greater, at least50-fold greater, at least 60-fold greater, at least 70-fold greater, atleast 80-fold greater, at least 90-fold greater, at least 100-foldgreater, or at least 1,000-fold greater, or more, than the affinity ofan antibody for unrelated amino acid sequences. Affinity of an antibodyto a target protein can be, for example, from about 100 nanomolar (nM)to about 0.1 nM, from about 100 nM to about 1 picomolar (pM), or fromabout 100 nM to about 1 femtomolar (fM) or more. As used herein, theterm “avidity” refers to the resistance of a complex of two or moreagents to dissociation after dilution. The terms “immunoreactive” and“preferentially binds” are used interchangeably herein with respect toantibodies and/or antigen-binding fragments.

The term “binding” refers to a direct association between two molecules,due to, for example, covalent, electrostatic, hydrophobic, and ionicand/or hydrogen-bond interactions, including interactions such as saltbridges and water bridges. A subject anti-C1s antibody bindsspecifically to an epitope within a complement C1s protein. “Specificbinding” refers to binding with an affinity of at least about 10⁻⁷ M orgreater, e.g., 5×10⁻⁷ M, 10⁻⁸ M, 5×10⁻⁸M, and greater. “Non-specificbinding” refers to binding with an affinity of less than about 10⁻⁷ M,e.g., binding with an affinity of 10⁻⁶M, 10⁻⁵ M, 10⁻⁴ M, etc.

As used herein, the term “CDR” or “complementarity determining region”is intended to mean the non-contiguous antigen combining sites foundwithin the variable region of both heavy and light chain polypeptides.CDRs have been described by Kabat et al., J. Biol. Chem. 252:6609-6616(1977); Kabat et al., U.S. Dept. of Health and Human Services,“Sequences of proteins of immunological interest” (1991) (also referredto herein as Kabat 1991); by Chothia et al., J. Mol. Biol. 196:901-917(1987) (also referred to herein as Chothia 1987); and MacCallum et al.,J. Mol. Biol. 262:732-745 (1996), where the definitions includeoverlapping or subsets of amino acid residues when compared against eachother. Nevertheless, application of either definition to refer to a CDRof an antibody or grafted antibodies or variants thereof is intended tobe within the scope of the term as defined and used herein. The aminoacid residues, which encompass the CDRs, as defined by each of the abovecited references are set forth below in Table 1 as a comparison. TheCDRs listed in Table 2 were defined in accordance with Kabat 1991.

TABLE 1 CDR Definitions Kabat¹ Chothia² MacCallum³ V_(H) CDR-1 31-3526-32 30-35 V_(H) CDR-2 50-65 53-55 47-58 V_(H) CDR-3  95-102  96-101 93-101 V_(L) CDR-1 24-34 26-32 30-36 V_(L) CDR-2 50-56 50-52 46-55V_(L) CDR-3 89-97 91-96 89-96 ¹Residue numbering follows thenomenclature of Kabat et al., supra ²Residue numbering follows thenomenclature of Chothia et al., supra ³Residue numbering follows thenomenclature of MacCallum et al., supra

As used herein, the terms “CDR-L1”, “CDR-L2”, and “CDR-L3” refer,respectively, to the first, second, and third CDRs in a light chainvariable region. As used herein, the terms “CDR-H1”, “CDR-H2”, and“CDR-H3” refer, respectively, to the first, second, and third CDRs in aheavy chain variable region. As used herein, the terms “CDR-1”, “CDR-2”,and “CDR-3” refer, respectively, to the first, second and third CDRs ofeither chain's variable region.

As used herein, the term “framework” when used in reference to anantibody variable region is intended to mean all amino acid residuesoutside the CDR regions within the variable region of an antibody. Avariable region framework is generally a discontinuous amino acidsequence between about 100-120 amino acids in length but is intended toreference only those amino acids outside of the CDRs. As used herein,the term “framework region” is intended to mean each domain of theframework that is separated by the CDRs.

An “isolated” antibody is one that has been identified and separatedand/or recovered from a component of its natural environment.Contaminant components of its natural environment are materials thatwould interfere with diagnostic or therapeutic uses for the antibody,and can include enzymes, hormones, and other proteinaceous ornonproteinaceous solutes. In some embodiments, the antibody will bepurified (1) to greater than 90%, greater than 95%, or greater than 98%,by weight of antibody as determined by the Lowry method, for example,more than 99% by weight, (2) to a degree sufficient to obtain at least15 residues of N-terminal or internal amino acid sequence by use of aspinning cup sequenator, or (3) to homogeneity by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) under reducing ornonreducing conditions using Coomassie blue or silver stain. Isolatedantibody includes the antibody in situ within recombinant cells since atleast one component of the antibody's natural environment will not bepresent. In some instances, isolated antibody will be prepared by atleast one purification step.

The terms “polypeptide,” “peptide,” and “protein”, used interchangeablyherein, refer to a polymeric form of amino acids of any length, whichcan include genetically coded and non-genetically coded amino acids,chemically or biochemically modified or derivatized amino acids, andpolypeptides having modified peptide backbones. The term includes fusionproteins, including, but not limited to, fusion proteins with aheterologous amino acid sequence, fusions with heterologous andhomologous leader sequences, with or without N-terminal methionineresidues; immunologically tagged proteins; and the like.

As used herein, the terms “treatment,” “treating,” “treat” and the like,refer to obtaining a desired pharmacologic and/or physiologic effect.The effect can be prophylactic in terms of completely or partiallypreventing a disease or symptom thereof and/or can be therapeutic interms of a partial or complete cure for a disease and/or adverse effectattributable to the disease. “Treatment,” as used herein, covers anytreatment of a disease in a mammal, particularly in a human, andincludes: (a) preventing the disease from occurring in a subject whichcan be predisposed to the disease but has not yet been diagnosed ashaving it; (b) inhibiting the disease, i.e., arresting its development;and (c) relieving the disease, i.e., causing regression of the disease.

The terms “individual,” “subject,” “host,” and “patient,” usedinterchangeably herein, refer to a mammal, including, but not limitedto, murines (rats, mice), non-human primates, humans, canines, felines,ungulates (e.g., equines, bovines, ovines, porcines, caprines), etc.Also encompassed by these terms are any animal that has a complementsystem, such as mammals, fish, and some invertebrates. As such theseterms include complement system-containing mammal, fish, andinvertebrate companion animals, agricultural animals, work animals, zooanimals, and lab animals.

A “therapeutically effective amount” or “efficacious amount” refers tothe amount of an anti-complement C1s antibody that, when administered toa mammal or other subject for treating a disease, is sufficient toeffect such treatment for the disease. The “therapeutically effectiveamount” will vary depending on the anti-complement C1s antibody, thedisease and its severity and the age, weight, etc., of the subject to betreated.

A “biological sample” encompasses a variety of sample types obtainedfrom an individual and can be used in a diagnostic or monitoring assay.The definition encompasses blood and other liquid samples of biologicalorigin, solid tissue samples such as a biopsy specimen or tissuecultures or cells derived therefrom and the progeny thereof. Thedefinition also includes samples that have been manipulated in any wayafter their procurement, such as by treatment with reagents,solubilization, or enrichment for certain components, such aspolynucleotides. The term “biological sample” encompasses a clinicalsample, and also includes cells in culture, cell supernatants, celllysates, serum, plasma, biological fluid, and tissue samples. The term“biological sample” includes urine, saliva, cerebrospinal fluid,interstitial fluid, ocular fluid, synovial fluid, blood fractions suchas plasma and serum, and the like. The term “biological sample” alsoincludes solid tissue samples, tissue culture samples, and cellularsamples.

Before the present invention is further described, it is to beunderstood that this invention is not limited to particular embodimentsdescribed, as such can, of course, vary. It is also to be understoodthat the terminology used herein is for the purpose of describingparticular embodiments only, and is not intended to be limiting, sincethe scope of the present invention will be limited only by the appendedclaims.

Where a range of values is provided, it is understood that eachintervening value, to the tenth of the unit of the lower limit unlessthe context clearly dictates otherwise, between the upper and lowerlimit of that range and any other stated or intervening value in thatstated range, is encompassed within the invention. The upper and lowerlimits of these smaller ranges can independently be included in thesmaller ranges, and are also encompassed within the invention, subjectto any specifically excluded limit in the stated range. Where the statedrange includes one or both of the limits, ranges excluding either orboth of those included limits are also included in the invention.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Although any methods andmaterials similar or equivalent to those described herein can also beused in the practice or testing of the present invention, the preferredmethods and materials are now described. All publications mentionedherein are incorporated herein by reference to disclose and describe themethods and/or materials in connection with which the publications arecited.

It must be noted that as used herein and in the appended claims, thesingular forms “a,” “an,” and “the” include plural referents unless thecontext clearly dictates otherwise. Thus, for example, reference to “ahumanized anti-complement C1s antibody” includes a plurality of suchantibodies and reference to “the complement-mediated diseases” includesreference to one or more complement-mediated diseases and equivalentsthereof known to those skilled in the art, and so forth. It is furthernoted that the claims can be drafted to exclude any optional element. Assuch, this statement is intended to serve as antecedent basis for use ofsuch exclusive terminology as “solely,” “only” and the like inconnection with the recitation of claim elements, or use of a “negative”limitation.

It is appreciated that certain features of the invention, which are, forclarity, described in the context of separate embodiments, can also beprovided in combination in a single embodiment. Conversely, variousfeatures of the invention, which are, for brevity, described in thecontext of a single embodiment, can also be provided separately or inany suitable sub-combination. All combinations of the embodimentspertaining to the invention are specifically embraced by the presentinvention and are disclosed herein just as if each and every combinationwas individually and explicitly disclosed. In addition, allsub-combinations of the various embodiments and elements thereof arealso specifically embraced by the present invention and are disclosedherein just as if each and every such sub-combination was individuallyand explicitly disclosed herein.

The publications discussed herein are provided solely for theirdisclosure prior to the filing date of the present application. Nothingherein is to be construed as an admission that the present invention isnot entitled to antedate such publication by virtue of prior invention.Further, the dates of publication provided can be different from theactual publication dates, which may need to be independently confirmed.

DETAILED DESCRIPTION

The present disclosure provides an antibody that binds complement C1sprotein (i.e., an anti-complement C1s antibody, also referred to hereinas an anti-C1s antibody and a C1s antibody) and a nucleic acid moleculethat encodes such an antibody. The present disclosure also providescompositions comprising such antibodies, and methods to produce and usesuch antibodies, nucleic acid molecules, and compositions. The presentdisclosure provides methods of treating a complement-mediated disease ordisorder, involving administering an anti-C1s antibody. The presentdisclosure further provides in vitro and in vivo detection methods usingan anti-C1s antibody described herein.

Anti-Complement C1s Antibodies

The present disclosure provides anti-complement C1s antibodies andpharmaceutical compositions comprising such antibodies. Complement C1sis an attractive target as it is upstream in the complement cascade andhas a narrow range of substrate specificity. Furthermore it is possibleto obtain antibodies (for example, but not limited to, monoclonalantibodies) that specifically bind the activated form of C1s.

The present disclosure provides an isolated antibody that specificallybinds an epitope within a complement C1s protein. As used herein, unlessdenoted otherwise, a complement C1s protein is an activated C1s protein.In some embodiments, an isolated anti-C1s antibody of the presentdisclosure binds an activated C1s protein. In some embodiments, anisolated anti-C1s antibody of the present disclosure binds an inactiveform of C1s. In other instances, an isolated anti-C1s antibody of thepresent disclosure binds both an activated C1s protein and an inactiveform of C1s. In some instances, the antibody is humanized, e.g., one ormore framework regions of the heavy chain variable region and/or thelight chain variable region include sequences derived from a humanimmunoglobulin framework.

The present disclosure provides an isolated monoclonal antibody thatinhibits cleavage of C4, where the isolated monoclonal antibody does notinhibit cleavage of C2. In some cases, the isolated monoclonal antibodyis humanized. In some cases, the antibody inhibits a component of theclassical complement pathway. In some cases, the component of theclassical complement pathway that is inhibited by the antibody is C1s.The present disclosure also provides methods of treating acomplement-mediated disease or disorder, the method comprisingadministering to an individual in need thereof an effective amount of anisolated monoclonal antibody that inhibits cleavage of C4, or apharmaceutical composition comprising the isolated monoclonal antibody,where the isolated monoclonal antibody does not inhibit cleavage of C2.

The present disclosure provides an isolated monoclonal antibody thatinhibits cleavage of C4 by C1s, i.e., inhibits C1s-mediated proteolyticcleavage of C4. In some cases, the isolated monoclonal antibody ishumanized. In some cases, the antibody inhibits cleavage of C4 by C1s byinhibiting binding of C4 to C1s; for example, in some cases, theantibody inhibits C1s-mediated cleavage of C4 by inhibiting binding ofC4 to a C4 binding site of C1s. Thus, in some cases, the antibodyfunctions as a competitive inhibitor. The present disclosure alsoprovides methods of treating a complement-mediated disease or disorder,the method comprising administering to an individual in need thereof aneffective amount of an isolated monoclonal antibody that inhibitscleavage of C4 by C1s, i.e., inhibits C1s-mediated proteolytic cleavageof C4.

The present disclosure provides an isolated monoclonal antibody thatinhibits cleavage of C4 by C1s, where the antibody does not inhibitcleavage of complement component C2 by C1s; i.e., the antibody inhibitsC1s-mediated cleavage of C4, but does not inhibit C1s-mediated cleavageof C2. In some cases, the isolated monoclonal antibody is humanized. Insome cases, the monoclonal antibody inhibits binding of C4 to C1s, butdoes not inhibit binding of C2 to C1s. The present disclosure alsoprovides methods of treating a complement-mediated disease or disorder,the method comprising administering to an individual in need thereof aneffective amount of an isolated monoclonal antibody that inhibitscleavage of C4 by C1s, where the antibody does not inhibit cleavage ofcomplement component C2 by C1s; i.e., the antibody inhibits C1s-mediatedcleavage of C4, but does not inhibit C1s-mediated cleavage of C2. Insome embodiments of the method, the antibody is humanized.

The present disclosure provides an isolated humanized monoclonalantibody that specifically binds an epitope within a region encompassingdomains IV and V of C1s. For example, the present disclosure provides anisolated humanized monoclonal antibody that specifically binds anepitope within amino acids 272-422 of the amino acid sequence depictedin FIG. 1 and set forth in SEQ ID NO:9. In some cases, the isolatedhumanized monoclonal antibody specifically binds an epitope within aminoacids 272-422 of the amino acid sequence depicted in FIG. 1 and setforth in SEQ ID NO:9, and inhibits binding of C4 to C1s. The presentdisclosure also provides methods of treating a complement-mediateddisease or disorder, the method comprising administering to anindividual in need thereof an effective amount of an isolated humanizedmonoclonal antibody that specifically binds an epitope within aminoacids 272-422 of the amino acid sequence depicted in FIG. 1 and setforth in SEQ ID NO:9, and inhibits binding of C4 to C1s.

The present disclosure provides an isolated humanized monoclonalantibody that specifically binds a conformational epitope within aregion encompassing domains IV and V of C1s. For example, the presentdisclosure provides an isolated humanized monoclonal antibody thatspecifically binds a conformational epitope within amino acids 272-422of the amino acid sequence depicted in FIG. 1 and set forth in SEQ IDNO:9. In some cases, the isolated humanized monoclonal antibodyspecifically binds a conformational epitope within amino acids 272-422of the amino acid sequence depicted in FIG. 1 and set forth in SEQ IDNO:9, and inhibits binding of C4 to C1s. The present disclosure alsoprovides methods of treating a complement-mediated disease or disorder,the method comprising administering to an individual in need thereof aneffective amount of an isolated humanized monoclonal antibody thatspecifically binds a conformational epitope within amino acids 272-422of the amino acid sequence depicted in FIG. 1 and set forth in SEQ IDNO:9, and inhibits binding of C4 to C1s.

The present disclosure provides an isolated monoclonal antibody thatbinds complement component C1s in a C1 complex. The C1 complex iscomposed of 6 molecules of C1q, 2 molecules of C1r, and 2 molecules ofC1s. In some cases, the isolated monoclonal antibody is humanized. Thus,in some cases, the present disclosure provides an isolated humanizedmonoclonal antibody that binds complement component C1s in a C1 complex.In some cases, the antibody binds C1s present in a C1 complex with highavidity.

Humanization of a framework region(s) reduces the risk of the antibodyeliciting a human-anti-mouse-antibody (HAMA) response in humans.Art-recognized methods of determining immune response can be performedto monitor a HAMA response in a particular patient or during clinicaltrials. Patients administered humanized antibodies can be given animmunogenicity assessment at the beginning and throughout theadministration of the therapy. The HAMA response is measured, forexample, by detecting antibodies to the humanized therapeutic reagent,in serum samples from the patient using a method known to one in theart, including surface plasmon resonance technology (BIACORE) and/orsolid-phase enzyme-linked immunosorbent assay (ELISA) analysis. In manycases, a subject humanized anti-C1s antibody does not substantiallyelicit a HAMA response in a human subject.

Certain amino acids from the human variable region framework residuesare selected for substitution based on their possible influence on CDRconformation and/or binding antigen. The unnatural juxtaposition ofmurine CDR regions with human variable framework region can result inunnatural conformational restraints, which, unless corrected bysubstitution of certain amino acid residues, lead to loss of bindingaffinity.

The selection of amino acid residues for substitution can be determined,in part, by computer modeling. Computer hardware and software forproducing three-dimensional images of immunoglobulin molecules are knownin the art. In general, molecular models are produced starting fromsolved structures for immunoglobulin chains or domains thereof. Thechains to be modeled are compared for amino acid sequence similaritywith chains or domains of solved three-dimensional structures, and thechains or domains showing the greatest sequence similarity is/areselected as starting points for construction of the molecular model.Chains or domains sharing at least 50% sequence identity are selectedfor modeling, e.g., those sharing at least 60%, at least 70%, at least80%, at least 90% sequence identity or more are selected for modeling.The solved starting structures are modified to allow for differencesbetween the actual amino acids in the immunoglobulin chains or domainsbeing modeled, and those in the starting structure. The modifiedstructures are then assembled into a composite immunoglobulin. Finally,the model is refined by energy minimization and by verifying that allatoms are within appropriate distances from one another and that bondlengths and angles are within chemically acceptable limits.

CDR and framework regions are as defined by Kabat, Sequences of Proteinsof Immunological Interest (National Institutes of Health, Bethesda, Md.,1987 and 1991). An alternative structural definition has been proposedby Chothia et al., J. Mol. Biol. 196:901 (1987); Nature 342:878 (1989);and J. Mol. Biol. 186:651 (1989) (collectively referred to as“Chothia”). When framework residues, as defined by Kabat, supra,constitute structural loop residues as defined by Chothia, supra, theamino acids present in the mouse antibody can be selected forsubstitution into the humanized antibody. Residues that are “adjacent toa CDR region” include amino acid residues in positions immediatelyadjacent to one or more of the CDRs in the primary sequence of thehumanized immunoglobulin chain, for example, in positions immediatelyadjacent to a CDR as defined by Kabat, or a CDR as defined by Chothia(See e.g., Chothia and Lesk JMB 196:901 (1987)). These amino acids areparticularly likely to interact with the amino acids in the CDRs and, ifchosen from the acceptor, to distort the donor CDRs and reduce affinity.Moreover, the adjacent amino acids can interact directly with theantigen (Amit et al., Science, 233:747 (1986)) and selecting these aminoacids from the donor can be desirable to keep all the antigen contactsthat provide affinity in the original antibody.

In some embodiments, an anti-C1s antibody of the present disclosure(e.g., a subject antibody that specifically binds an epitope in acomplement C1s protein) comprises: a) a light chain region comprisingone, two, or three V_(L) CDRs of an IPN003 antibody; and b) a heavychain region comprising one, two, or three V_(H) CDRs of an IPN003antibody; where the V_(H) and V_(L) CDRs are as defined by Kabat (see,e.g., Table 1, above; and Kabat 1991). In some of these embodiments, theanti-C1s antibody includes a humanized V_(H) and/or V_(L) frameworkregion (FR).

In some embodiments, an anti-C1s antibody of the present disclosure(e.g., a subject antibody that specifically binds an epitope in acomplement C1s protein) comprises: a) a light chain region comprisingone, two, or three V_(L) CDRs of an IPN003 antibody; and b) a heavychain region comprising one, two, or three V_(H) CDRs of an IPN003antibody; where the V_(H) and V_(L) CDRs are as defined by Chothia (see,e.g., Table 1, above; and Chothia 1987). In some of these embodiments,the anti-C1s antibody includes a humanized V_(H) and/or V_(L) frameworkregion.

CDR amino acid sequences, and V_(L) and V_(H) amino acid sequences, ofIPN003 antibody are provided in Table 2 (FIG. 2). Table 2 also providesthe SEQ ID NOs assigned to each of the amino acid sequences.

In some embodiments, an anti-C1s antibody of the present disclosure(e.g., a subject antibody that specifically binds an epitope in acomplement C1s protein) comprises: a) a light chain region comprisingone, two, or three CDRs selected from SEQ ID NO:1, SEQ ID NO:2, and SEQID NO:3; and b) a heavy chain region comprising one, two, or three CDRsselected from SEQ ID NO:4, SEQ ID NO:5, and SEQ ID NO:6. In some ofthese embodiments, the anti-C1s antibody includes a humanized V_(H)and/or V_(L) framework region.

SEQ ID NO: 1: SSVSSSYLHWYQ; SEQ ID NO: 2: STSNLASGVP; SEQ ID NO: 3:HQYYRLPPIT; SEQ ID NO: 4: GFTFSNYAMSWV; SEQ ID NO: 5: ISSGGSHTYY;SEQ ID NO: 6: ARLFTGYAMDY.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a CDR having an amino acid sequence selected from the groupconsisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ IDNO:5, and SEQ ID NO:6.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a light chain variable region comprising amino acid sequencesSEQ ID NO:1, SEQ ID NO:2, and SEQ ID NO:3.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a heavy chain variable region comprising amino acid sequencesSEQ ID NO:4, SEQ ID NO:5, and SEQ ID NO:6.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a CDR-L1 having amino acid sequence SEQ ID NO:1, a CDR-L2having amino acid sequence SEQ ID NO:2, a CDR-L3 having amino acidsequence SEQ ID NO:3, a CDR-H1 having amino acid sequence SEQ ID NO:4, aCDR-H2 having amino acid sequence SEQ ID NO:5, and a CDR-H3 having aminoacid sequence SEQ ID NO:6.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a light chain variable region comprising an amino acidsequence that is 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98% or 99% identical to the amino acid sequence set forth inSEQ ID NO:7.

SEQ ID NO: 7: DIVMTQTTAIMSASLGERVTMTCTASSSVSSSYLHWYQQKPGSSPKLWIYSTSNLASGVPARFSGSGSGTFYSLTISSMEAEDDATYYCHQYYRLP PITFGAGTKLELK.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a heavy chain variable region comprising an amino acidsequence that is 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98% or 99% identical to the amino acid sequence set forth inSEQ ID NO:8.

SEQ ID NO: 8: QVKLEESGGALVKPGGSLKLSCAASGFTFSNYAMSWVRQIPEKRLEWVATISSGGSHTYYLDSVKGRFTISRDNARDTLYLQMSSLRSEDTALYYC ARLFTGYAMDYWGQGTSVT.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a light chain variable region comprising an amino acidsequence that is 90% identical to amino acid sequence SEQ ID NO:7.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a heavy chain variable region comprising an amino acidsequence that is 90% identical to amino acid sequence SEQ ID NO:8.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a light chain variable region comprising amino acid sequenceSEQ ID NO:7.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a heavy chain variable region comprising amino acid sequenceSEQ ID NO:8.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a light chain variable region comprising an amino acidsequence that is 90% identical to amino acid sequence SEQ ID NO:7 and aheavy chain variable region comprising an amino acid sequence that is90% identical to amino acid sequence SEQ ID NO:8.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a light chain variable region comprising amino acid sequenceSEQ ID NO:7 and a heavy chain variable region comprising amino acidsequence SEQ ID NO:8.

In some embodiments, an anti-C1s antibody of the present disclosurespecifically binds an epitope within the complement C1s protein, whereinthe antibody competes for binding the epitope with an antibody thatcomprises light chain CDRs of an antibody light chain variable regioncomprising amino acid sequence SEQ ID NO:7 and heavy chain CDRs of anantibody heavy chain variable region comprising amino acid sequence SEQID NO:8.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises light chain CDRs of an antibody light chain variable regioncomprising amino acid sequence SEQ ID NO:7 and heavy chain CDRs of anantibody heavy chain variable region comprising amino acid sequence SEQID NO:8.

In some cases, a humanized V_(H) framework or V_(L) framework is aconsensus human framework. A consensus humanized framework can representthe most commonly occurring amino acid residue in a selection of humanimmunoglobulin V_(L) or V_(H) framework sequences.

Non-limiting examples of consensus human V_(H) framework regionssuitable for use with V_(H) CDRs as described herein include (subgroupIII consensus):

(SEQ ID NO: 53) a) V_(H) FR1: EVQLVESGGGLVQPGGSLRLSCAAS; (SEQ ID NO: 54)b) V_(H) FR2: WVRQAPGKGLEWV; (SEQ ID NO: 55) c)V_(H) FR3: RFTISRDNSKNTLYLQMNSLRAEDTAVYYC; and (SEQ ID NO: 56) d)V_(H) FR4: WGQGTLVTVSS.

In some cases, V_(H) FR3 comprises an amino acid substitution atposition 71, 73, and/or 78; e.g., where the underlined and bolded R inRFTISRDNSKNTLYLQMNSLRAEDTAVYYC (SEQ ID NO:55) is amino acid 71 (Kabatnumbering); the underlined and bolded N inRFTISRDNSKNTLYLQMNSLRAEDTAVYYC (SEQ ID NO:55) is amino acid 73 (Kabatnumbering); and the underlined and bolded L inRFTISRDNSKNTLYLQMNSLRAEDTAVYYC (SEQ ID NO:55) is amino acid 78 (Kabatnumbering). For example, in some cases, amino acid 71 is A; and/or aminoacid 73 is T; and/or amino acid 78 is A. As an example, in some cases, asuitable consensus humanized V_(H) FR3 comprises the amino acidsequence: RFTISADTSKNTAYLQMNSLRAEDTAVYYC (SEQ ID NO:57).

Non-limiting examples of consensus human V_(H) framework regionssuitable for use with V_(H) CDRs as described herein include (subgroup Iconsensus):

(SEQ ID NO: 58) a) V_(H) FR1: QVQLVQSGAEVKKPGASVKVSCKAS; (SEQ ID NO: 59)b) V_(H) FR2: WVRQAPGQGLEWM; (SEQ ID NO: 60) c)V_(H) FR3: RVTITADTSTSTAYMELSSLRSEDTAVYYC; and (SEQ ID NO: 56) d)V_(H) FR4: WGQGTLVTVSS.

Non-limiting examples of consensus human V_(H) framework regionssuitable for use with V_(H) CDRs as described herein include (subgroupII consensus):

(SEQ ID NO: 61) a) V_(H) FR1: QVQLQESGPGLVKPSQTLSLTCTVS; (SEQ ID NO: 62)b) V_(H) FR2: WIRQPPGKGLEWI; (SEQ ID NO: 63) c)V_(H) FR3: RVTISVDTSKNQFSLKLSSVTAADTAVYYC; and (SEQ ID NO: 56) d)V_(H) FR4: WGQGTLVTVSS.

Non-limiting examples of consensus human V_(L) framework regionssuitable for use with V_(L) CDRs as described herein include (subgroup Iconsensus):

(SEQ ID NO: 57) a) V_(L) FR1: DIQMTQSPSSLSASVGDRVTITC; (SEQ ID NO: 58)b) V_(L) FR2: WYQQKPGKAPKLLIY; (SEQ ID NO: 59) c)V_(L) FR3: GVPSRFSGSGSGTDFTLTISSLQPEDFATYYC; and (SEQ ID NO: 60) d)V_(L) FR4: FGQGTKVEIK.

Non-limiting examples of consensus human V_(L) framework regionssuitable for use with V_(L) CDRs as described herein include (subgroupII consensus):

(SEQ ID NO: 64) a) V_(L) FR1: DIVMTQSPLSLPVTPGEPASISC; (SEQ ID NO: 65)b) V_(L) FR2: WYLQKPGQSPQLLIY; (SEQ ID NO: 66) c)V_(L) FR3: GVPDRFSGSGSGTDFTLKISRVEAEDVGVYYC; and (SEQ ID NO: 60) d)V_(L) FR4: FGQGTKVEIK.

Non-limiting examples of consensus human V_(L) framework regionssuitable for use with V_(L) CDRs as described herein include (subgroupIII consensus):

(SEQ ID NO: 67) a) V_(L) FR1: DIVMTQSPDSLAVSLGERATINC; (SEQ ID NO: 68)b) V_(L) FR2: WYQQKPGQPPKLLIY; (SEQ ID NO: 69) c)V_(L) FR3: GVPDRFSGSGSGTDFTLTISSLQAEDFAVYYC; and (SEQ ID NO: 60) d)V_(L) FR4: FGQGTKVEIK.

Non-limiting examples of consensus human V_(L) framework regionssuitable for use with V_(L) CDRs as described herein include (subgroupIV consensus):

(SEQ ID NO: 67) a) V_(L) FR1: DIVMTQSPDSLAVSLGERATINC; (SEQ ID NO: 68)b) V_(L) FR2: WYQQKPGQPPKLLIY; (SEQ ID NO: 69) c)V_(L) FR3: GVPDRFSGSGSGTDFTLTISSLQAEDFAVYYC; and (SEQ ID NO: 60) d)V_(L) FR4: FGQGTKVEIK.

In some embodiments, an anti-C1s antibody of the present disclosurebinds a complement C1s protein from an individual that has a complementsystem. In some embodiments, an anti-C1s antibody of the presentdisclosure binds a complement C1s protein from a mammal, fish, orinvertebrate that has a complement system. In some embodiments, ananti-C1s antibody of the present disclosure binds a mammalian complementC1s protein. In some embodiments, an anti-C1s antibody of the presentdisclosure binds a human complement C1s protein. In some embodiments, ananti-C1s antibody of the present disclosure binds a rat complement C1sprotein. In some embodiments, an anti-C1s antibody of the presentdisclosure binds a complement C1s protein having SEQ ID NO:9). Aminoacid sequence SEQ ID NO:9 represents Homo sapiens complement C1sprotein, which has the amino acid sequence set forth in FIG. 1.

In some embodiments, an anti-C1s antibody of the present disclosurebinds a complement C1s protein with a dissociation constant (K_(D)) ofno more than 2.5 nM. In some embodiments, an anti-C1s antibody of thepresent disclosure binds a complement C1s protein with a K_(D) of nomore than 2 nM. In some embodiments, an anti-C1s antibody of the presentdisclosure binds a complement C1s protein with a K_(D) of no more than 1nM. In some embodiments, an anti-C1s antibody of the present disclosurebinds a complement C1s protein with a K_(D) of no more than 0.9 nM, nomore than 0.8 nM, no more than 0.7 nM, no more than 0.6 nM, no more than0.5 nM, no more than 0.4 nM, no more than 0.3 nM, no more than 0.2 nM,no more than 0.1 nM. In some embodiments, an anti-C1s antibody of thepresent disclosure binds a complement C1s protein with a K_(D) of nomore than 0.3 nM. In some embodiments, an anti-C1s antibody of thepresent disclosure binds a complement C1s protein with a K_(D) of nomore than 0.2 nM. In some embodiments, an anti-C1s antibody of thepresent disclosure binds a complement C1s protein with a K_(D) of nomore than 0.1 nM. Methods to measure binding of an antibody to C1sprotein can be determined by one skilled in the art.

In some embodiments, an anti-C1s antibody of the present disclosurebinds a complement C1s protein with a K_(D) of no more than 90 pM, nomore than 80 pM, no more than 70 pM, no more than 60 pM, no more than 50pM, no more than 40 pM, no more than 30 pM, no more than 20 pM, no morethan 10 pM, no more than 9 pM, no more than 8 pM, no more than 7 pM, nomore than 6 pM, no more than 5 pM, no more than 4 pM, no more than 3 pM,no more than 2 pM, no more than 1 pM.

In some embodiments, an anti-C1s antibody of the present disclosurebinds a human complement C1s protein with a dissociation constant(K_(D)) of no more than 2.5 nM. In some embodiments, an anti-C1santibody of the present disclosure binds a human complement C1s proteinwith a K_(D) of no more than 2 nM. In some embodiments, an anti-C1santibody of the present disclosure binds a human complement C1s proteinwith a K_(D) of no more than 1 nM. In some embodiments, an anti-C1santibody of the present disclosure binds a human complement C1s proteinwith a K_(D) of no more than 0.9 nM, no more than 0.8 nM, no more than0.7 nM, no more than 0.6 nM, no more than 0.5 nM, no more than 0.4 nM,no more than 0.3 nM, no more than 0.2 nM, no more than 0.1 nM. In someembodiments, an anti-C1s antibody of the present disclosure binds ahuman complement C1s protein with a K_(D) of no more than 0.3 nM. Insome embodiments, an anti-C1s antibody of the present disclosure binds ahuman complement C1s protein with a K_(D) of no more than 0.2 nM. Insome embodiments, an anti-C1s antibody of the present disclosure binds ahuman complement C1s protein with a K_(D) of no more than 0.1 nM.Methods to measure binding of an antibody to human C1s protein can bedetermined by one skilled in the art. In some embodiments, a bindingassay as described in the Examples is used to determine the K_(D)between an antibody and a human C1s protein.

In some embodiments, an anti-C1s antibody of the present disclosurebinds a human complement C1s protein with a K_(D) of no more than 90 pM,no more than 80 pM, no more than 70 pM, no more than 60 pM, no more than50 pM, no more than 40 pM, no more than 30 pM, no more than 20 pM, nomore than 10 pM, no more than 9 pM, no more than 8 pM, no more than 7pM, no more than 6 pM, no more than 5 pM, no more than 4 pM, no morethan 3 pM, no more than 2 pM, no more than 1 pM.

In some embodiments, an anti-C1s antibody of the present disclosure thatbinds human complement C1s protein also binds a complement C1s proteinof another species. In some embodiments, an anti-C1s antibody of thepresent disclosure that binds human complement C1s protein also binds arodent complement C1s protein. Examples of rodent complement C1sproteins include, but are not limited to, guinea pig C1s proteins,hamster C1s proteins, mouse C1s proteins, and rat C1s proteins. In someembodiments, an anti-C1s antibody of the present disclosure that bindshuman complement C1s protein also binds a lagomorph complement C1sprotein, e.g., a rabbit C1s protein. In some embodiments, an anti-C1santibody of the present disclosure that binds human complement C1sprotein also binds a non-human primate complement C1s protein, whereexemplary non-human primates include monkeys such as Macaca mulatta, andMacaca fascicularis. In some embodiments, such a cross-reactive antibodybinds the complement C1s protein of another (non-human) species with aK_(D) of a similar order of magnitude as the antibody binds a humancomplement C1s protein. In some embodiments an anti-C1s antibody of thepresent disclosure binds a rat complement C1s protein. In someembodiments an anti-C1s antibody of the present disclosure that bindshuman complement C1s protein also binds a rat complement C1s protein.

In some embodiments, an anti-C1s antibody of the present disclosurebinds a rat complement C1s protein with a dissociation constant (K_(D))of no more than 2.5 nM. In some embodiments, an anti-C1s antibody of thepresent disclosure binds a rat complement C1s protein with a K_(D) of nomore than 2 nM. In some embodiments, an anti-C1s antibody of the presentdisclosure binds a rat complement C1s protein with a K_(D) of no morethan 1 nM. In some embodiments, an anti-C1s antibody of the presentdisclosure binds a rat complement C1s protein with a K_(D) of no morethan 0.9 nM, no more than 0.8 nM, no more than 0.7 nM, no more than 0.6nM, no more than 0.5 nM, no more than 0.4 nM, no more than 0.3 nM, nomore than 0.2 nM, no more than 0.1 nM. In some embodiments, an anti-C1santibody of the present disclosure binds a rat complement C1s proteinwith a K_(D) of no more than 0.3 nM. In some embodiments, an anti-C1santibody of the present disclosure binds a rat complement C1s proteinwith a K_(D) of no more than 0.2 nM. In some embodiments, an anti-C1santibody of the present disclosure binds a rat complement C1s proteinwith a K_(D) of no more than 0.1 nM. Methods to measure binding of anantibody to rat C1s protein can be determined by one skilled in the art.In some embodiments, a binding assay as described in the Examples isused to determine the K_(D) between an antibody and a rat C1s protein.

In some embodiments, an anti-C1s antibody of the present disclosurebinds a rat complement C1s protein with a K_(D) of no more than 90 pM,no more than 80 pM, no more than 70 pM, no more than 60 pM, no more than50 pM, no more than 40 pM, no more than 30 pM, no more than 20 pM, nomore than 10 pM, no more than 9 pM, no more than 8 pM, no more than 7pM, no more than 6 pM, no more than 5 pM, no more than 4 pM, no morethan 3 pM, no more than 2 pM, no more than 1 pM.

In some embodiments, an anti-C1s antibody of the present disclosurebinds both native complement C1s protein and denatured complement C1sprotein. “Native protein” as used herein refers to protein as folded inits naturally-occurring physiological state, and thus excludes denaturedprotein. Detection of binding can be conducted by western blot. In suchembodiments, an anti-C1s antibody of the present disclosure binds C1sprotein applied to a native gel and also binds C1s protein applied to adenatured (e.g., sodium dodecyl sulfate (SDS)) gel. In some embodiments,a subject anti-C1s antibody of the present disclosure binds a linearepitope in C1s. Methods to determine if an antibody binds a native C1sprotein or a denatured C1s protein are known to those skilled in theart. In some embodiments, gel electrophoresis is used to determine if anantibody binds a native and/or a denatured C1s protein.

In some embodiments, an anti-C1s antibody of the present disclosurereduces production of C4b2a (i.e., complement C4b and C2a complex; alsoknown as “C3 convertase”) by at least 10%, at least 20%, at least 30%,at least 40%, at least 50%, at least 60%, at least 65%, at least 70%, atleast 75%, at least 80%, at least 85%, at least 90%, at least 95%, or100%, compared to the amount of C4b2a produced in the absence of asubject anti-C1s antibody. Methods to measure production of C4b2a areknown in the art.

In some embodiments, an anti-C1s antibody of the present disclosureinhibits cleavage of at least one substrate cleaved by complement C1sprotein. In some embodiments, the substrate is selected from the groupconsisting of complement C2 and complement C4. In some embodiments, thesubstrate is complement C2. In some embodiments the substrate iscomplement C4. In some embodiments, an anti-C1s antibody of the presentdisclosure inhibits cleavage of complement C2. In some embodiments, ananti-C1s antibody of the present disclosure inhibits cleavage ofcomplement C4. In some embodiments, an anti-C1s antibody of the presentdisclosure inhibits cleavage of complement C2 and complement C4.

In some embodiments, an anti-C1s antibody of the present disclosureinhibits cleavage of at least one substrate cleaved by human complementC1s protein. In some embodiments, the substrate is selected from thegroup consisting of human complement C2 and human complement C4. In someembodiments, the substrate is human complement C2. In some embodimentsthe substrate is human complement C4. In some embodiments, an anti-C1santibody of the present disclosure inhibits cleavage of human complementC2. In some embodiments, an anti-C1s antibody of the present disclosureinhibits cleavage of human complement C4. In some embodiments, ananti-C1s antibody of the present disclosure inhibits cleavage of humancomplement C2 and human complement C4. In some embodiments, an anti-C1santibody of the present disclosure inhibits rat C1s-mediated cleavage ofhuman complement C4. In some embodiments, an anti-C1s antibody of thepresent disclosure inhibits human C1s-mediated cleavage of humancomplement C4.

In some embodiments, an anti-C1s antibody of the present disclosureinhibits cleavage of at least one substrate cleaved by rat complementC1s protein. In some embodiments, the substrate is selected from thegroup consisting of rat complement C2 and rat complement C4. In someembodiments, the substrate is rat complement C2. In some embodiments thesubstrate is rat complement C4. In some embodiments, an anti-C1santibody of the present disclosure inhibits cleavage of rat complementC2. In some embodiments, an anti-C1s antibody of the present disclosureinhibits cleavage of rat complement C4. In some embodiments, an anti-C1santibody of the present disclosure inhibits cleavage of rat complementC2 and rat complement C4.

In some embodiments, an anti-C1s antibody of the present disclosureinhibits C1s by sterically blocking access to the C1s active site or bysterically blocking access to the substrate.

In some embodiments, an anti-C1s antibody of the present disclosureinhibits C1s-mediated activation of complement C4. For example, in somecases, an anti-C1s antibody of the present disclosure inhibitsC1s-mediated activation of complement C4 with an IC₅₀ less than50×10⁻⁹M, less than 25×10⁻⁹ M, less than 10×10⁻⁹ M, less than 5×10⁻⁹M,less than 1×10⁻⁹M, less than 0.5×10⁻⁹ M, less than 0.1×10⁻⁹ M, or lessthan 0.1×10⁻¹⁰ M.

In some instances, an anti-C1s antibody of the present disclosureinhibits complement-mediated cell lysis, e.g., in an in vitro cell lysisassay. For example, in some instances, an anti-C1s antibody of thepresent disclosure inhibits complement-mediated cell lysis with an IC₅₀of less than 10×10⁻⁹ M, less than 5×10⁻⁹M, less than 1×10⁻⁹M, less than0.5×10⁻⁹ M, less than 0.1×10⁻⁹ M, or less than 0.1×10⁻¹⁰ M.

In some embodiments, an anti-C1s antibody of the present disclosurecompetes for binding the epitope bound by IPN003.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a variable domain of an IPN003 antibody.

In some embodiments, an anti-C1s antibody of the present disclosure isan IPN003 antibody.

The present disclosure provides for any anti-C1s antibody of theembodiments to be humanized. In some embodiments, an anti-C1s antibodyof the present disclosure comprises a humanized framework region. Insome embodiments, an anti-C1s antibody of the present disclosurecomprises a humanized light chain framework region. In some embodiments,an anti-C1s antibody of the present disclosure comprises a humanizedheavy chain framework region.

In some embodiments, a subject anti-C1s antibody comprises one or morehumanized framework regions (FRs). In some embodiments, a subjectanti-C1s antibody comprises a light chain variable region comprisingone, two, three, or four light chain FRs that have been humanized. Insome embodiments, a subject antibody comprises a light chain variableregion comprising, in order from N-terminus to C-terminus: a humanizedlight chain FR1; a CDR-L1 as set forth herein; a humanized light chainFR2; a CDR-L2 as set forth herein; a humanized light chain FR3; a CDR-L3as set forth herein; and a humanized light chain FR4. In someembodiments, the respective amino acid sequences of CDR-L1, CDR-L2, andCDR-L3 are: SEQ ID NO:1, SEQ ID NO:2, and SEQ ID NO:3.

For example, a subject antibody can comprise a light chain variableregion that comprises, in order from N-terminus to C-terminus: ahumanized light chain FR1; a CDR-L1 comprising amino acid sequence SEQID NO:1; a humanized light chain FR2; a CDR-L2 comprising amino acidsequence SEQ ID NO:2; a humanized light chain FR3; a CDR-L3 comprisingamino acid sequence SEQ ID NO:3; and a humanized light chain FR4.

In some embodiments, a subject anti-C1s antibody comprises a heavy chainvariable region comprising one, two, three, or four heavy chain FRs thathave been humanized. In some embodiments, a subject antibody comprises aheavy chain variable region comprising, in order from N-terminus toC-terminus: a humanized heavy chain FR1; a CDR-H1 as set forth herein; ahumanized heavy chain FR2; a CDR-H2 as set forth herein; a humanizedheavy chain FR3; a CDR-H3 as set forth herein; and a humanized heavychain FR4.

For example, a subject antibody can comprise a heavy chain variableregion that comprises, in order from N-terminus to C-terminus: ahumanized heavy chain FR1; a CDR-H1 comprising amino acid sequence SEQID NO:4; a humanized heavy chain FR2; a CDR-H2 comprising amino acidsequence SEQ ID NO:5; a humanized heavy chain FR3; a CDR-H3 comprisingamino acid sequence SEQ ID NO:6; and a humanized heavy chain FR4.

In some embodiments, an anti-C1s antibody of the present disclosure(e.g., a subject antibody that specifically binds an epitope in acomplement C1s protein) comprises: a) a light chain region comprisingone, two, or three CDRs selected from SEQ ID NO:32, SEQ ID NO:33, andSEQ ID NO:3; and b) a heavy chain region comprising one, two, or threeCDRs selected from SEQ ID NO:34, SEQ ID NO:35, and SEQ ID NO:36. In someof these embodiments, the anti-C1s antibody includes a humanized V_(H)and/or V_(L) framework region.

SEQ ID NO: 32: TASSSVSSSYLH; SEQ ID NO: 33: STSNLAS; SEQ ID NO: 3:HQYYRLPPIT; SEQ ID NO: 34: NYAMS; SEQ ID NO: 35: TISSGGSHTYYLDSVKG;SEQ ID NO: 36: LFTGYAMDY.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a CDR having an amino acid sequence selected from the groupconsisting of SEQ ID NO:32, SEQ ID NO:33, SEQ ID NO:3, SEQ ID NO:34, SEQID NO:35, and SEQ ID NO:36.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a light chain variable region comprising amino acid sequencesSEQ ID NO:32, SEQ ID NO:33, and SEQ ID NO:3.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a heavy chain variable region comprising amino acid sequencesSEQ ID NO:34, SEQ ID NO:35, and SEQ ID NO:36.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a CDR-L1 having amino acid sequence SEQ ID NO:32, a CDR-L2having amino acid sequence SEQ ID NO:33, a CDR-L3 having amino acidsequence SEQ ID NO:3, a CDR-H1 having amino acid sequence SEQ ID NO:34,a CDR-H2 having amino acid sequence SEQ ID NO:35, and a CDR-H3 havingamino acid sequence SEQ ID NO:36.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a light chain variable region comprising an amino acidsequence that is 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98% or 99% identical to the amino acid sequence set forth inSEQ ID NO:37.

SEQ ID NO: 37: QIVLTQSPAIMSASLGERVTMTCTASSSVSSSYLHWYQQKPGSSPKLWIYSTSNLASGVPARFSGSGSGTFYSLTISSMEAEDDATYYCHQYYRLP PITFGAGTKLELK.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a heavy chain variable region comprising an amino acidsequence that is 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98% or 99% identical to the amino acid sequence set forth inSEQ ID NO:38.

SEQ ID NO: 38: EVMLVESGGALVKPGGSLKLSCAASGFTFSNYAMSWVRQIPEKRLEWVATISSGGSHTYYLDSVKGRFTISRDNARDTLYLQMSSLRSEDTALYYC ARLFTGYAMDYWGQGTSVTVSS.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a light chain variable region comprising an amino acidsequence that is 90% identical to amino acid sequence SEQ ID NO:37.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a heavy chain variable region comprising an amino acidsequence that is 90% identical to amino acid sequence SEQ ID NO:38.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a light chain variable region comprising amino acid sequenceSEQ ID NO:37.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a heavy chain variable region comprising amino acid sequenceSEQ ID NO:38.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a light chain variable region comprising an amino acidsequence that is 90% identical to amino acid sequence SEQ ID NO:37 and aheavy chain variable region comprising an amino acid sequence that is90% identical to amino acid sequence SEQ ID NO:38.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a light chain variable region comprising an amino acidsequence that is 95% identical to amino acid sequence SEQ ID NO:37 and aheavy chain variable region comprising an amino acid sequence that is95% identical to amino acid sequence SEQ ID NO:38.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a light chain variable region comprising amino acid sequenceSEQ ID NO:37 and a heavy chain variable region comprising amino acidsequence SEQ ID NO:38.

In some embodiments, an anti-C1s antibody of the present disclosurespecifically binds an epitope within the complement C1s protein, whereinthe antibody competes for binding the epitope with an antibody thatcomprises light chain CDRs of an antibody light chain variable regioncomprising amino acid sequence SEQ ID NO:37 and heavy chain CDRs of anantibody heavy chain variable region comprising amino acid sequence SEQID NO:38.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises light chain CDRs of an antibody light chain variable regioncomprising amino acid sequence SEQ ID NO:37 and heavy chain CDRs of anantibody heavy chain variable region comprising amino acid sequence SEQID NO:38.

In some embodiments, a subject anti-C1s antibody comprises one or morehumanized framework regions (FRs). In some embodiments, a subjectanti-C1s antibody comprises a light chain variable region comprisingone, two, three, or four light chain FRs that have been humanized. Insome embodiments, a subject antibody comprises a light chain variableregion comprising, in order from N-terminus to C-terminus: a humanizedlight chain FR1; a CDR-L1 as set forth herein; a humanized light chainFR2; a CDR-L2 as set forth herein; a humanized light chain FR3; a CDR-L3as set forth herein; and a humanized light chain FR4. In someembodiments, the respective amino acid sequences of CDR-L1, CDR-L2, andCDR-L3 are: SEQ ID NO:32, SEQ ID NO:33, and SEQ ID NO:3.

For example, a subject antibody can comprise a light chain variableregion that comprises, in order from N-terminus to C-terminus: ahumanized light chain FR1; a CDR-L1 comprising amino acid sequence SEQID NO:32; a humanized light chain FR2; a CDR-L2 comprising amino acidsequence SEQ ID NO:33; a humanized light chain FR3; a CDR-L3 comprisingamino acid sequence SEQ ID NO:3; and a humanized light chain FR4.

In some embodiments, a subject anti-C1s antibody comprises a heavy chainvariable region comprising one, two, three, or four heavy chain FRs thathave been humanized. In some embodiments, a subject antibody comprises aheavy chain variable region comprising, in order from N-terminus toC-terminus: a humanized heavy chain FR1; a CDR-H1 as set forth herein; ahumanized heavy chain FR2; a CDR-H2 as set forth herein; a humanizedheavy chain FR3; a CDR-H3 as set forth herein; and a humanized heavychain FR4.

For example, a subject antibody can comprise a heavy chain variableregion that comprises, in order from N-terminus to C-terminus: ahumanized heavy chain FR1; a CDR-H1 comprising amino acid sequence SEQID NO:34; a humanized heavy chain FR2; a CDR-H2 comprising amino acidsequence SEQ ID NO:35; a humanized heavy chain FR3; a CDR-H3 comprisingamino acid sequence SEQ ID NO:36; and a humanized heavy chain FR4.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a light chain variable region comprising an amino acidsequence that is 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98% or 99% identical to the amino acid sequence set forth inSEQ ID NO:37.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a heavy chain variable region comprising an amino acidsequence that is 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98% or 99% identical to the amino acid sequence set forth inSEQ ID NO:38.

A subject anti-C1s antibody can comprise a heavy chain variable regioncomprising an amino acid sequence that is 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to theamino acid sequence set forth in SEQ ID NO:39 and depicted in FIG. 16(VH variant 1).

A subject anti-C1s antibody can comprise a heavy chain variable regioncomprising an amino acid sequence that is 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to theamino acid sequence set forth in SEQ ID NO:40 and depicted in FIG. 17(VH variant 2).

A subject anti-C1s antibody can comprise a heavy chain variable regioncomprising an amino acid sequence that is 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to theamino acid sequence set forth in SEQ ID NO:41 and depicted in FIG. 18(VH variant 3).

A subject anti-C1s antibody can comprise a heavy chain variable regioncomprising an amino acid sequence that is 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to theamino acid sequence set forth in SEQ ID NO:42 and depicted in FIG. 19(VH variant 4).

A subject anti-C1s antibody can comprise a light chain variable regioncomprising an amino acid sequence that is 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to theamino acid sequence set forth in SEQ ID NO:43 and depicted in FIG. 20(VK variant 1).

A subject anti-C1s antibody can comprise a light chain variable regioncomprising an amino acid sequence that is 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to theamino acid sequence set forth in SEQ ID NO:44 and depicted in FIG. 21(VK variant 2).

A subject anti-C1s antibody can comprise a light chain variable regioncomprising an amino acid sequence that is 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to theamino acid sequence set forth in SEQ ID NO:45 and depicted in FIG. 22(VK variant 3).

A subject anti-C1s antibody can comprise a heavy chain variable regioncomprising 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 of the framework(FR) amino acid substitutions, relative to the IPN003 parental antibodyFR amino acid sequences, depicted in Table 7 (FIG. 23).

For example, a subject anti-C1s antibody can comprise a heavy chainvariable region comprising an M→Q substitution at amino acid position 3in VH FR1 and/or an A→G substitution at amino acid position 10 in VH FR1and/or a K→R substitution at amino acid position 19 in VH FR1.

As another example, a subject anti-C1s antibody can comprise a heavychain variable region comprising an I→A substitution at amino acidposition 40 in VH FR2 and/or an E→G substitution at amino acid position42 in VH FR2 and/or an R→G substitution at amino acid position 44 in VHFR2.

As another example, a subject anti-C1s antibody can comprise a heavychain variable region comprising an A→S substitution at amino acidposition 74 in VH FR3 and/or an R→K substitution at amino acid position75 in VH FR3 and/or a D→N substitution at amino acid position 76 in VHFR3 and/or an S→N amino acid substitution at amino acid position 82A inVH FR3 and/or an S→A amino acid substitution at amino acid position 84in VH FR3.

As another example, a subject anti-C1s antibody can comprise a heavychain variable region comprising an S→L substitution at amino acidposition 108 in VH FR4.

A subject anti-C1s antibody can comprise a light chain variable regioncomprising 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or18 of the framework (FR) amino acid substitutions, relative to theIPN003 parental antibody FR amino acid sequence depicted in Table 8(FIG. 23).

For example, a subject anti-C1s antibody can comprise a light chainvariable region comprising an I→T substitution at position 10 in VL FR1and/or an M→L substitution at amino acid position 11 in VL FR1 and/or anA→L substitution at position 13 of VL FR1 and/or an L→P substitution atposition 15 in VL FR1 and/or a V→A substitution at amino acid position19 in VL FR1 and/or an M→L substitution at amino acid position 21 in VLFR1 and/or a T→S substitution at amino acid position 22 in VL FR1.

As another example, a subject anti-C1s antibody can comprise a lightchain variable region comprising an S→K substitution at amino acidposition 42 in VL FR2 and/or an S→A substitution at amino acid position43 in VL FR2.

As another example, a subject anti-C1s antibody can comprise a lightchain variable region comprising an A→S substitution at amino acidposition 60 in VL FR3 and/or an F→D substitution at amino acid position70 in VL FR3 and/or an S→T substitution at amino acid position 72 in VLFR3 and/or an M→L substitution at amino acid position 78 in VL FR3and/or an E→Q substitution at amino acid position 79 in VL FR3 and/or anA→P substitution at amino acid position 80 in VL FR3 and/or a D→Fsubstitution at amino acid position 83 in VL FR3.

As another example, a subject anti-C1s antibody can comprise a lightchain variable region comprising an A→Q substitution at amino acidposition 100 in VL FR4 and/or an L→I substitution at amino acid position106 in VL FR4.

In some cases, an anti-C1s antibody of the present disclosure comprises:

i) a VH variant 1 comprising the amino acid sequence depicted in FIG. 16and set forth in SEQ ID NO:39; and a Vk variant 1 comprising the aminoacid sequence depicted in FIG. 20 and set forth in SEQ ID NO:43;

ii) a VH variant 1 comprising the amino acid sequence depicted in FIG.16 and set forth in SEQ ID NO:39; and a Vk variant 2 comprising theamino acid sequence depicted in FIG. 21 and set forth in SEQ ID NO:44;

iii) a VH variant 1 comprising the amino acid sequence depicted in FIG.16 and set forth in SEQ ID NO:39; and a Vk variant 3 comprising theamino acid sequence depicted in FIG. 22 and set forth in SEQ ID NO:45;

iv) a VH variant 2 comprising the amino acid sequence depicted in FIG.17 and set forth in SEQ ID NO:40; and a Vk variant 1 comprising theamino acid sequence depicted in FIG. 20 and set forth in SEQ ID NO:43;

v) a VH variant 2 comprising the amino acid sequence depicted in FIG. 17and set forth in SEQ ID NO:40; and a Vk variant 2 comprising the aminoacid sequence depicted in FIG. 21 and set forth in SEQ ID NO:44;

vi) a VH variant 2 comprising the amino acid sequence depicted in FIG.17 and set forth in SEQ ID NO:40; and a Vk variant 3 comprising theamino acid sequence depicted in FIG. 22 and set forth in SEQ ID NO:45;

vii) a VH variant 3 comprising the amino acid sequence depicted in FIG.18 and set forth in SEQ ID NO:41; and a Vk variant 1 comprising theamino acid sequence depicted in FIG. 20 and set forth in SEQ ID NO:43;

viii) a VH variant 3 comprising the amino acid sequence depicted in FIG.18 and set forth in SEQ ID NO:41; and a Vk variant 2 comprising theamino acid sequence depicted in FIG. 21 and set forth in SEQ ID NO:44;

ix) a VH variant 3 comprising the amino acid sequence depicted in FIG.18 and set forth in SEQ ID NO:41; and a Vk variant 3 comprising theamino acid sequence depicted in FIG. 22 and set forth in SEQ ID NO:45;

x) a VH variant 4 comprising the amino acid sequence depicted in FIG. 19and set forth in SEQ ID NO:42; and a Vk variant 1 comprising the aminoacid sequence depicted in FIG. 20 and set forth in SEQ ID NO:43;

xi) a VH variant 4 comprising the amino acid sequence depicted in FIG.19 and set forth in SEQ ID NO:42; and a Vk variant 2 comprising theamino acid sequence depicted in FIG. 21 and set forth in SEQ ID NO:44;or

xii) a VH variant 4 comprising the amino acid sequence depicted in FIG.19 and set forth in SEQ ID NO:42; and a Vk variant 3 comprising theamino acid sequence depicted in FIG. 22 and set forth in SEQ ID NO:45.

In some embodiments, an anti-C1s antibody of the present disclosure isan Ig monomer or an antigen-binding fragment thereof that binds acomplement C1s protein. In some embodiments, an anti-C1s antibody of thepresent disclosure is an Ig monomer. In some embodiments, an anti-C1santibody of the present disclosure is an antigen-binding fragment of anIg monomer that binds a complement C1s protein.

In some embodiments, an anti-C1s antibody of the present disclosure isselected from the group consisting of an Ig monomer, a Fab fragment, aF(ab′)₂ fragment, a Fd fragment, a scFv, a scAb, a dAb, a Fv, a singledomain heavy chain antibody, and a single domain light chain antibody.

In some embodiments, an anti-C1s antibody of the present disclosure isselected the group consisting of a mono-specific antibody, a bi-specificantibody, and a multi-specific antibody.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a light chain region and a heavy chain region that are presentin separate polypeptides.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises a light chain region and a heavy chain region that are presentin a single polypeptide.

In some embodiments, a subject antibody comprises anti-C1s heavy chainCDRs and anti-C1s light chain CDRs in a single polypeptide chain, e.g.,in some embodiments, a subject antibody is a scFv.

In some embodiments, a subject antibody comprises, in order fromN-terminus to C-terminus: a first amino acid sequence of from about 5amino acids to about 25 amino acids in length; a CDR-L1; a second aminoacid sequence of from about 5 amino acids to about 25 amino acids inlength; a CDR-L2; a third amino acid sequence of from about 5 aminoacids to about 25 amino acids in length; a CDR-L3; a fourth amino acidsequence of from about 5 amino acids to about 25 amino acids in length;a CDR-H1; a fifth amino acid sequence of from about 5 amino acids toabout 25 amino acids in length; a CDR-H2; a sixth amino acid sequence offrom about 5 amino acids to about 25 amino acids in length; a CDR-H3;and a seventh amino acid sequence of from about 5 amino acids to about25 amino acids in length. In some embodiments, the respective amino acidsequences of CDR-L1, CDR-L2, CDR-L3, CDR-H1, CDR-H2, and CDR-H3 are: SEQID NO:32, SEQ ID NO:33, SEQ ID NO:3, SEQ ID NO:34, SEQ ID NO:35, and SEQID NO:36. For example, in some embodiments, a subject antibodycomprises, in order from N-terminus to C-terminus: a first amino acidsequence of from about 5 amino acids to about 25 amino acids in length;a CDR-L1 comprising the amino acid sequence set forth in SEQ ID NO:32; asecond amino acid sequence of from about 5 amino acids to about 25 aminoacids in length; a CDR-L2 comprising the amino acid sequence set forthin SEQ ID NO:33; a third amino acid sequence of from about 5 amino acidsto about 25 amino acids in length; a CDR-L3 comprising the amino acidsequence set forth in SEQ ID NO:3; a fourth amino acid sequence of fromabout 5 amino acids to about 25 amino acids in length; a CDR-H1comprising the amino acid sequence set forth in SEQ ID NO:34; a fifthamino acid sequence of from about 5 amino acids to about 25 amino acidsin length; a CDR-H2 comprising the amino acid sequence set forth in SEQID NO:35; a sixth amino acid sequence of from about 5 amino acids toabout 25 amino acids in length; a CDR-H3 comprising the amino acidsequence set forth in SEQ ID NO:36; and a seventh amino acid sequence offrom about 5 amino acids to about 25 amino acids in length.

In some embodiments, a subject antibody comprises, in order fromN-terminus to C-terminus: a light chain FR1 region; a CDR-L1; a lightchain FR2 region; a CDR-L2; a light chain FR3 region; a CDR-L3;optionally a light chain FR4 region; a linker region; optionally a heavychain FR1 region; a CDR-H1; a heavy chain FR2 region; a CDR-H2; a heavychain FR3 region; a CDR-H3; and a heavy chain FR4 region. In someembodiments, the respective amino acid sequences of CDR-L1, CDR-L2,CDR-L3, CDR-H1, CDR-H2, and CDR-H3 are: SEQ ID NO:32, SEQ ID NO:33, SEQID NO:3, SEQ ID NO:34, SEQ ID NO:35, and SEQ ID NO:36. In some of theseembodiments, one or more of the FR regions is a humanized FR region. Insome of these embodiments, each of the FR regions is a humanized FRregion. The linker region can be from about 5 amino acids (aa) to about50 amino acids in length, e.g., from about 5 aa to about 10 aa, fromabout 10 aa to about 15 aa, from about 15 aa to about 20 aa, from about20 aa to about 25 aa, from about 25 aa to about 30 aa, from about 30 aato about 35 aa, from about 35 aa to about 40 aa, from about 40 aa toabout 45 aa, or from about 45 aa to about 50 aa in length.

In some embodiments, a subject antibody comprises, in order fromN-terminus to C-terminus: a first amino acid sequence of from about 5amino acids to about 25 amino acids in length; a CDR-H1; a second aminoacid sequence of from about 5 amino acids to about 25 amino acids inlength; a CDR-H2; a third amino acid sequence of from about 5 aminoacids to about 25 amino acids in length; a CDR-H3; a fourth amino acidsequence of from about 5 amino acids to about 25 amino acids in length;a CDR-L1; a fifth amino acid sequence of from about 5 amino acids toabout 25 amino acids in length; a CDR-L2; a sixth amino acid sequence offrom about 5 amino acids to about 25 amino acids in length; a CDR-L3;and a seventh amino acid sequence of from about 5 amino acids to about25 amino acids in length. In some embodiments, the respective amino acidsequences of CDR-L1, CDR-L2, CDR-L3, CDR-H1, CDR-H2, and CDR-H3 are: SEQID NO:32, SEQ ID NO:33, SEQ ID NO:3, SEQ ID NO:34, SEQ ID NO:35, and SEQID NO:36. For example, in some embodiments, a subject antibodycomprises, in order from N-terminus to C-terminus: a first amino acidsequence of from about 5 amino acids to about 25 amino acids in length;a CDR-H1 comprising the amino acid sequence set forth in SEQ ID NO:34; asecond amino acid sequence of from about 5 amino acids to about 25 aminoacids in length; a CDR-H2 comprising the amino acid sequence set forthin SEQ ID NO:35; a third amino acid sequence of from about 5 amino acidsto about 25 amino acids in length; a CDR-H3 comprising the amino acidsequence set forth in SEQ ID NO:36; a fourth amino acid sequence of fromabout 5 amino acids to about 25 amino acids in length; a CDR-L1comprising the amino acid sequence set forth in SEQ ID NO:32; a fifthamino acid sequence of from about 5 amino acids to about 25 amino acidsin length; a CDR-L2 comprising the amino acid sequence set forth in SEQID NO:33; a sixth amino acid sequence of from about 5 amino acids toabout 25 amino acids in length; a CDR-L3 comprising the amino acidsequence set forth in SEQ ID NO:3; and a seventh amino acid sequence offrom about 5 amino acids to about 25 amino acids in length.

In some embodiments, a subject antibody comprises, in order fromN-terminus to C-terminus: a heavy chain FR1 region; a CDR-H1; a heavychain FR2 region; a CDR-H2; a heavy chain FR3 region; a CDR-H3;optionally a heavy chain FR4 region; a linker; optionally a light chainFR1 region; a CDR-L1; a light chain FR2 region; a CDR-L2; a light chainFR3 region; a CDR-L3; and a light chain FR4 region. In some embodiments,the respective amino acid sequences of CDR-L1, CDR-L2, CDR-L3, CDR-H1,CDR-H2, and CDR-H3 are: SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ IDNO:34, SEQ ID NO:35, and SEQ ID NO:36. In some of these embodiments, oneor more of the FR regions is a humanized FR region. In some of theseembodiments, each of the FR regions is a humanized FR region. The linkerregion can be from about 5 amino acids to about 50 amino acids inlength, e.g., from about 5 aa to about 10 aa, from about 10 aa to about15 aa, from about 15 aa to about 20 aa, from about 20 aa to about 25 aa,from about 25 aa to about 30 aa, from about 30 aa to about 35 aa, fromabout 35 aa to about 40 aa, from about 40 aa to about 45 aa, or fromabout 45 aa to about 50 aa in length.

In some embodiments, a subject antibody comprises, in order fromN-terminus to C-terminus: a first amino acid sequence of from about 5amino acids to about 25 amino acids in length; a CDR-L1; a second aminoacid sequence of from about 5 amino acids to about 25 amino acids inlength; a CDR-L2; a third amino acid sequence of from about 5 aminoacids to about 25 amino acids in length; a CDR-L3; a fourth amino acidsequence of from about 5 amino acids to about 25 amino acids in length;a CDR-H1; a fifth amino acid sequence of from about 5 amino acids toabout 25 amino acids in length; a CDR-H2; a sixth amino acid sequence offrom about 5 amino acids to about 25 amino acids in length; a CDR-H3;and a seventh amino acid sequence of from about 5 amino acids to about25 amino acids in length. In some embodiments, the respective amino acidsequences of CDR-L1, CDR-L2, CDR-L3, CDR-H1, CDR-H2, and CDR-H3 are: SEQID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, and SEQ IDNO:6. For example, in some embodiments, a subject antibody comprises, inorder from N-terminus to C-terminus: a first amino acid sequence of fromabout 5 amino acids to about 25 amino acids in length; a CDR-L1comprising the amino acid sequence set forth in SEQ ID NO:1; a secondamino acid sequence of from about 5 amino acids to about 25 amino acidsin length; a CDR-L2 comprising the amino acid sequence set forth in SEQID NO:2; a third amino acid sequence of from about 5 amino acids toabout 25 amino acids in length; a CDR-L3 comprising the amino acidsequence set forth in SEQ ID NO:3; a fourth amino acid sequence of fromabout 5 amino acids to about 25 amino acids in length; a CDR-H1comprising the amino acid sequence set forth in SEQ ID NO:4; a fifthamino acid sequence of from about 5 amino acids to about 25 amino acidsin length; a CDR-H2 comprising the amino acid sequence set forth in SEQID NO:5; a sixth amino acid sequence of from about 5 amino acids toabout 25 amino acids in length; a CDR-H3 comprising the amino acidsequence set forth in SEQ ID NO:6; and a seventh amino acid sequence offrom about 5 amino acids to about 25 amino acids in length.

In some embodiments, a subject antibody comprises, in order fromN-terminus to C-terminus: a light chain FR1 region; a CDR-L1; a lightchain FR2 region; a CDR-L2; a light chain FR3 region; a CDR-L3;optionally a light chain FR4 region; a linker region; optionally a heavychain FR1 region; a CDR-H1; a heavy chain FR2 region; a CDR-H2; a heavychain FR3 region; a CDR-H3; and a heavy chain FR4 region. In someembodiments, the respective amino acid sequences of CDR-L1, CDR-L2,CDR-L3, CDR-H1, CDR-H2, and CDR-H3 are: SEQ ID NO:1, SEQ ID NO:2, SEQ IDNO:3, SEQ ID NO:4, SEQ ID NO:5, and SEQ ID NO:6. In some of theseembodiments, one or more of the FR regions is a humanized FR region. Insome of these embodiments, each of the FR regions is a humanized FRregion. The linker region can be from about 5 amino acids (aa) to about50 amino acids in length, e.g., from about 5 aa to about 10 aa, fromabout 10 aa to about 15 aa, from about 15 aa to about 20 aa, from about20 aa to about 25 aa, from about 25 aa to about 30 aa, from about 30 aato about 35 aa, from about 35 aa to about 40 aa, from about 40 aa toabout 45 aa, or from about 45 aa to about 50 aa in length.

In some embodiments, a subject antibody comprises, in order fromN-terminus to C-terminus: a first amino acid sequence of from about 5amino acids to about 25 amino acids in length; a CDR-H1; a second aminoacid sequence of from about 5 amino acids to about 25 amino acids inlength; a CDR-H2; a third amino acid sequence of from about 5 aminoacids to about 25 amino acids in length; a CDR-H3; a fourth amino acidsequence of from about 5 amino acids to about 25 amino acids in length;a CDR-L1; a fifth amino acid sequence of from about 5 amino acids toabout 25 amino acids in length; a CDR-L2; a sixth amino acid sequence offrom about 5 amino acids to about 25 amino acids in length; a CDR-L3;and a seventh amino acid sequence of from about 5 amino acids to about25 amino acids in length. In some embodiments, the respective amino acidsequences of CDR-L1, CDR-L2, CDR-L3, CDR-H1, CDR-H2, and CDR-H3 are: SEQID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, and SEQ IDNO:6. For example, in some embodiments, a subject antibody comprises, inorder from N-terminus to C-terminus: a first amino acid sequence of fromabout 5 amino acids to about 25 amino acids in length; a CDR-H1comprising the amino acid sequence set forth in SEQ ID NO:4; a secondamino acid sequence of from about 5 amino acids to about 25 amino acidsin length; a CDR-H2 comprising the amino acid sequence set forth in SEQID NO:5; a third amino acid sequence of from about 5 amino acids toabout 25 amino acids in length; a CDR-H3 comprising the amino acidsequence set forth in SEQ ID NO:6; a fourth amino acid sequence of fromabout 5 amino acids to about 25 amino acids in length; a CDR-L1comprising the amino acid sequence set forth in SEQ ID NO:1; a fifthamino acid sequence of from about 5 amino acids to about 25 amino acidsin length; a CDR-L2 comprising the amino acid sequence set forth in SEQID NO:2; a sixth amino acid sequence of from about 5 amino acids toabout 25 amino acids in length; a CDR-L3 comprising the amino acidsequence set forth in SEQ ID NO:3; and a seventh amino acid sequence offrom about 5 amino acids to about 25 amino acids in length.

In some embodiments, a subject antibody comprises, in order fromN-terminus to C-terminus: a heavy chain FR1 region; a CDR-H1; a heavychain FR2 region; a CDR-H2; a heavy chain FR3 region; a CDR-H3;optionally a heavy chain FR4 region; a linker; optionally a light chainFR1 region; a CDR-L1; a light chain FR2 region; a CDR-L2; a light chainFR3 region; a CDR-L3; and a light chain FR4 region. In some embodiments,the respective amino acid sequences of CDR-L1, CDR-L2, CDR-L3, CDR-H1,CDR-H2, and CDR-H3 are: SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ IDNO:4, SEQ ID NO:5, and SEQ ID NO:6. In some of these embodiments, one ormore of the FR regions is a humanized FR region. In some of theseembodiments, each of the FR regions is a humanized FR region. The linkerregion can be from about 5 amino acids to about 50 amino acids inlength, e.g., from about 5 aa to about 10 aa, from about 10 aa to about15 aa, from about 15 aa to about 20 aa, from about 20 aa to about 25 aa,from about 25 aa to about 30 aa, from about 30 aa to about 35 aa, fromabout 35 aa to about 40 aa, from about 40 aa to about 45 aa, or fromabout 45 aa to about 50 aa in length.

Linkers suitable for use a subject antibody include “flexible linkers”.If present, the linker molecules are generally of sufficient length topermit some flexible movement between linked regions. In someembodiments, the linker molecules are generally about 6-50 atoms long.The linker molecules can also be, for example, aryl acetylene, ethyleneglycol oligomers containing 2-10 monomer units, diamines, diacids, aminoacids, or combinations thereof. Other linker molecules that can bindpolypeptides can be used in light of this disclosure.

Suitable linkers can be readily selected and can be of any of a numberof suitable lengths, such as from 1 amino acid (e.g., Gly) to 20 aminoacids, from 2 amino acids to 15 amino acids, from 3 amino acids to 12amino acids, including 4 amino acids to 10 amino acids, 5 amino acids to9 amino acids, 6 amino acids to 8 amino acids, or 7 amino acids to 8amino acids, and can be 1, 2, 3, 4, 5, 6, or 7 amino acids.

Exemplary flexible linkers include glycine polymers (G)_(n),glycine-serine polymers (including, for example, (GS)_(n), (GSGGS)_(n)(SEQ ID NO:10) and (GGGS)_(n) (SEQ ID NO:11), where n is an integer ofat least one), glycine-alanine polymers, alanine-serine polymers, andother flexible linkers known in the art. Glycine and glycine-serinepolymers are of interest since both of these amino acids are relativelyunstructured, and therefore can serve as a neutral tether betweencomponents. Glycine polymers are of particular interest since glycineaccesses significantly more phi-psi space than even alanine, and is muchless restricted than residues with longer side chains (see Scheraga,Rev. Computational Chem. 11173-142 (1992)). Exemplary flexible linkersinclude, but are not limited GGSG (SEQ ID NO:12), GGSGG (SEQ ID NO:13),GSGSG (SEQ ID NO:14), GSGGG (SEQ ID NO:15), GGGSG (SEQ ID NO:16), GSSSG(SEQ ID NO:17), and the like. The ordinarily skilled artisan willrecognize that design of a peptide conjugated to any elements describedabove can include linkers that are all or partially flexible, such thatthe linker can include a flexible linker as well as one or more portionsthat confer less flexible structure.

In some embodiments, an anti-C1s antibody of the present disclosurecomprises scFv multimers. For example, in some embodiments, a subjectantibody is an scFv dimer (e.g., comprises two tandem scFv (scFv₂)), anscFv trimer (e.g., comprises three tandem scFv (scFv₃)), an scFvtetramer (e.g., comprises four tandem scFv (scFv₄)), or is a multimer ofmore than four scFv (e.g., in tandem). The scFv monomers can be linkedin tandem via linkers of from about 2 amino acids to about 10 aminoacids (aa) in length, e.g., 2 aa, 3 aa, 4 aa, 5 aa, 6 aa, 7 aa, 8 aa, 9aa, or 10 aa in length. Suitable linkers include, e.g., (Gly)_(x), wherex is an integer from 2 to 10. Other suitable linkers are those discussedabove. In some embodiments, each of the scFv monomers in a subject scFvmultimer is humanized, as described above.

In some cases, a subject antibody comprises a constant region of animmunoglobulin (e.g., an Fc region). The Fc region, if present, can be ahuman Fc region or an Fc region from any animal that has a complementsystem. In some embodiments, the Fc region, if present, is a human Fcregion. If constant regions are present, the antibody can contain bothlight chain and heavy chain constant regions. Suitable heavy chainconstant region include CH1, hinge, CH2, CH3, and CH4 regions. Theantibodies described herein include antibodies having all types ofconstant regions, including IgM, IgG, IgD, IgA and IgE, and any isotype,including IgG1, IgG2, IgG3 and IgG4. An example of a suitable heavychain Fc region is a human isotype IgG1 Fc. Another example of asuitable heavy chain Fc region is a human isotype IgG2 Fc. Yet anotherexample of a suitable heavy chain Fc region is a human isotype IgG3 Fc.Light chain constant regions can be lambda or kappa. A subject antibody(e.g., a subject humanized antibody) can comprise sequences from morethan one class or isotype. Antibodies can be expressed as tetramerscontaining two light and two heavy chains, as separate heavy chains,light chains, as Fab, Fab′, F(ab′)2, and Fv, or as single chainantibodies in which heavy and light chain variable domains are linkedthrough a spacer.

In some cases, the heavy chain region is of the isotype IgG4. In some ofthese embodiments, the hinge region comprises an S241P substitution.See, e.g., Angal et al. (1993) Mol. Immunol. 30:105. In some of theseembodiments, the hinge region comprises an L236E (or L235E, using EUnumbering; Kabat et al. (1991) Sequences of Proteins of ImmunologicalInterest, 5^(th) Ed. U.S. Dept. Health and Human Services, Bethesda,Md., NIH Publication No. 91-3242) substitution. See, e.g., Reddy et al.(2000) J. Immunol. 164:1925; and Klechevsky et al. (2010) Blood116:1685. In some of these embodiments, the hinge region comprises anS241P substitution and an L236E substitution.

A subject antibody can comprise a free thiol (—SH) group at the carboxylterminus, where the free thiol group can be used to attach the antibodyto a second polypeptide (e.g., another antibody, including a subjectantibody), a scaffold, a carrier, etc.

In some embodiments, a subject antibody comprises one or morenon-naturally occurring amino acids. In some embodiments, thenon-naturally encoded amino acid comprises a carbonyl group, an acetylgroup, an aminooxy group, a hydrazine group, a hydrazide group, asemicarbazide group, an azide group, or an alkyne group. See, e.g., U.S.Pat. No. 7,632,924 for suitable non-naturally occurring amino acids.Inclusion of a non-naturally occurring amino acid can provide forlinkage to a polymer, a second polypeptide, a scaffold, etc. Forexample, a subject antibody linked to a water-soluble polymer can bemade by reacting a water-soluble polymer (e.g., PEG) that comprises acarbonyl group to the antibody, where the antibody comprises anon-naturally encoded amino acid that comprises an aminooxy, hydrazine,hydrazide or semiexample ecarbazide group. As another example, a subjectantibody linked to a water-soluble polymer can be made by reacting asubject antibody that comprises an alkyne-containing amino acid with awater-soluble polymer (e.g., PEG) that comprises an azide moiety; insome embodiments, the azide or alkyne group is linked to the PEGmolecule through an amide linkage. A “non-naturally encoded amino acid”refers to an amino acid that is not one of the 20 common amino acids orpyrrolysine or selenocysteine. Other terms that can be used synonymouslywith the term “non-naturally encoded amino acid” are “non-natural aminoacid,” “unnatural amino acid,” “non-naturally-occurring amino acid,” andvariously hyphenated and non-hyphenated versions thereof. The term“non-naturally encoded amino acid” also includes, but is not limited to,amino acids that occur by modification (e.g. post-translationalmodifications) of a naturally encoded amino acid (including but notlimited to, the 20 common amino acids or pyrrolysine and selenocysteine)but are not themselves naturally incorporated into a growing polypeptidechain by the translation complex. Examples of suchnon-naturally-occurring amino acids include, but are not limited to,N-acetylglucosaminyl-L-serine, N-acetylglucosaminyl-L-threonine, andO-phosphotyrosine.

In some embodiments, a subject antibody is linked (e.g., covalentlylinked) to a polymer (e.g., a polymer other than a polypeptide).Suitable polymers include, e.g., biocompatible polymers, andwater-soluble biocompatible polymers. Suitable polymers includesynthetic polymers and naturally-occurring polymers. Suitable polymersinclude, e.g., substituted or unsubstituted straight or branched chainpolyalkylene, polyalkenylene or polyoxyalkylene polymers or branched orunbranched polysaccharides, e.g. a homo- or hetero-polysaccharide.Suitable polymers include, e.g., ethylene vinyl alcohol copolymer(commonly known by the generic name EVOH or by the trade name EVAL);polybutylmethacrylate; poly(hydroxyvalerate); poly(L-lactic acid);polycaprolactone; poly(lactide-co-glycolide); poly(hydroxybutyrate);poly(hydroxybutyrate-co-valerate); polydioxanone; polyorthoester;polyanhydride; poly(glycolic acid); poly(D,L-lactic acid); poly(glycolicacid-co-trimethylene carbonate); polyphosphoester; polyphosphoesterurethane; poly(amino acids); cyanoacrylates; poly(trimethylenecarbonate); poly(iminocarbonate); copoly(ether-esters) (e.g.,poly(ethylene oxide)-poly(lactic acid) (PEO/PLA) co-polymers);polyalkylene oxalates; polyphosphazenes; biomolecules, such as fibrin,fibrinogen, cellulose, starch, collagen and hyaluronic acid;polyurethanes; silicones; polyesters; polyolefins; polyisobutylene andethylene-alphaolefin copolymers; acrylic polymers and copolymers; vinylhalide polymers and copolymers, such as polyvinyl chloride; polyvinylethers, such as polyvinyl methyl ether; polyvinylidene halides, such aspolyvinylidene fluoride and polyvinylidene chloride; polyacrylonitrile;polyvinyl ketones; polyvinyl aromatics, such as polystyrene; polyvinylesters, such as polyvinyl acetate; copolymers of vinyl monomers witheach other and olefins, such as ethylene-methyl methacrylate copolymers,acrylonitrile-styrene copolymers, ABS resins, and ethylene-vinyl acetatecopolymers; polyamides, such as Nylon 66 and polycaprolactam; alkydresins; polycarbonates; polyoxymethylenes; polyimides; polyethers; epoxyresins; polyurethanes; rayon; rayon-triacetate; cellulose; celluloseacetate; cellulose butyrate; cellulose acetate butyrate; cellophane;cellulose nitrate; cellulose propionate; cellulose ethers; amorphousTeflon; poly(ethylene glycol); and carboxymethyl cellulose.

Suitable synthetic polymers include unsubstituted and substitutedstraight or branched chain poly(ethyleneglycol), poly(propyleneglycol)poly(vinylalcohol), and derivatives thereof, e.g., substitutedpoly(ethyleneglycol) such as methoxypoly(ethyleneglycol), andderivatives thereof. Suitable naturally-occurring polymers include,e.g., albumin, amylose, dextran, glycogen, and derivatives thereof.

Suitable polymers can have an average molecular weight in a range offrom 500 Da to 50,000 Da, e.g., from 5,000 Da to 40,000 Da, or from25,000 to 40,000 Da. For example, in some embodiments, where a subjectantibody comprises a poly(ethylene glycol) (PEG) ormethoxypoly(ethyleneglycol) polymer, the PEG ormethoxypoly(ethyleneglycol) polymer can have a molecular weight in arange of from about 0.5 kiloDaltons (kDa) to 1 kDa, from about 1 kDa to5 kDa, from 5 kDa to 10 kDa, from 10 kDa to 25 kDa, from 25 kDa to 40kDa, or from 40 kDa to 60 kDa.

As noted above, in some embodiments, a subject antibody is covalentlylinked to a non-peptide synthetic polymer. In some embodiments, asubject antibody is covalently linked to a PEG polymer. In someembodiments, a subject scFv multimer is covalently linked to a PEGpolymer. See, e.g., Albrecht et al. (2006) J. Immunol. Methods 310:100.Methods and reagents suitable for PEGylation of a protein are well knownin the art and can be found in, e.g., U.S. Pat. No. 5,849,860. PEGsuitable for conjugation to a protein is generally soluble in water atroom temperature, and has the general formula R(O—CH₂—CH₂)_(n)O—R, whereR is hydrogen or a protective group such as an alkyl or an alkanolgroup, and where n is an integer from 1 to 1,000. Where R is aprotective group, it generally has from 1 to 8 carbons.

In some embodiments, the PEG conjugated to the subject antibody islinear. In some embodiments, the PEG conjugated to the subject antibodyis branched. Branched PEG derivatives such as those described in U.S.Pat. No. 5,643,575, “star-PEG's” and multi-armed PEG's such as thosedescribed in Shearwater Polymers, Inc. catalog “Polyethylene GlycolDerivatives 1997-1998.” Star PEGs are described in the art including,e.g., in U.S. Pat. No. 6,046,305.

A subject antibody can be glycosylated, e.g., a subject antibody cancomprise a covalently linked carbohydrate or polysaccharide moiety.Glycosylation of antibodies is typically either N-linked or O-linkedN-linked refers to the attachment of the carbohydrate moiety to the sidechain of an asparagine residue. The tripeptide sequencesasparagine-X-serine and asparagine-X-threonine, where X is any aminoacid except proline, are the recognition sequences for enzymaticattachment of the carbohydrate moiety to the asparagine side chain.Thus, the presence of either of these tripeptide sequences in apolypeptide creates a potential glycosylation site. O-linkedglycosylation refers to the attachment of one of the sugarsN-acetylgalactosamine, galactose, or xylose to a hydroxyamino acid, mostcommonly serine or threonine, although 5-hydroxyproline or5-hydroxylysine can also be used.

Addition of glycosylation sites to an antibody is convenientlyaccomplished by altering the amino acid sequence such that it containsone or more of the above-described tripeptide sequences (for N-linkedglycosylation sites). The alteration can also be made by the additionof, or substitution by, one or more serine or threonine residues to thesequence of the original antibody (for O-linked glycosylation sites).Similarly, removal of glycosylation sites can be accomplished by aminoacid alteration within the native glycosylation sites of an antibody.

A subject antibody will in some embodiments comprise a “radiopaque”label, e.g. a label that can be easily visualized using for examplex-rays. Radiopaque materials are well known to those of skill in theart. The most common radiopaque materials include iodide, bromide orbarium salts. Other radiopaque materials are also known and include, butare not limited to organic bismuth derivatives (see, e.g., U.S. Pat. No.5,939,045), radiopaque multiurethanes (see U.S. Pat. No. 5,346,981),organobismuth composites (see, e.g., U.S. Pat. No. 5,256,334),radiopaque barium multimer complexes (see, e.g., U.S. Pat. No.4,866,132), and the like.

A subject antibody can be covalently linked to a second moiety (e.g., alipid, a polypeptide other than a subject antibody, a synthetic polymer,a carbohydrate, and the like) using for example, glutaraldehyde, ahomobifunctional cross-linker, or a heterobifunctional cross-linkerGlutaraldehyde cross-links polypeptides via their amino moieties.Homobifunctional cross-linkers (e.g., a homobifunctional imidoester, ahomobifunctional N-hydroxysuccinimidyl (NHS) ester, or ahomobifunctional sulfhydryl reactive cross-linker) contain two or moreidentical reactive moieties and can be used in a one-step reactionprocedure in which the cross-linker is added to a solution containing amixture of the polypeptides to be linked Homobifunctional NHS ester andimido esters cross-link amine containing polypeptides. In a mildalkaline pH, imido esters react only with primary amines to formimidoamides, and overall charge of the cross-linked polypeptides is notaffected. Homobifunctional sulfhydryl reactive cross-linkers includebismaleimidhexane (BMH), 1,5-difluoro-2,4-dinitrobenzene (DFDNB), and1,4-di-(3′,2′-pyridyldithio) propinoamido butane (DPDPB).

Heterobifunctional cross-linkers have two or more different reactivemoieties (e.g., amine reactive moiety and a sulfhydryl-reactive moiety)and are cross-linked with one of the polypeptides via the amine orsulfhydryl reactive moiety, then reacted with the other polypeptide viathe non-reacted moiety. Multiple heterobifunctional haloacetylcross-linkers are available, as are pyridyl disulfide cross-linkers.Carbodiimides are a classic example of heterobifunctional cross-linkingreagents for coupling carboxyls to amines, which results in an amidebond.

A subject antibody can be immobilized on a solid support. Suitablesupports are well known in the art and comprise, inter alia,commercially available column materials, polystyrene beads, latex beads,magnetic beads, colloid metal particles, glass and/or silicon chips andsurfaces, nitrocellulose strips, nylon membranes, sheets, duracytes,wells of reaction trays (e.g., multi-well plates), plastic tubes, etc. Asolid support can comprise any of a variety of substances, including,e.g., glass, polystyrene, polyvinyl chloride, polypropylene,polyethylene, polycarbonate, dextran, nylon, amylose, natural andmodified celluloses, polyacrylamides, agaroses, and magnetite. Suitablemethods for immobilizing a subject antibody onto a solid support arewell known and include, but are not limited to ionic, hydrophobic,covalent interactions and the like. Solid supports can be soluble orinsoluble, e.g., in aqueous solution. In some embodiments, a suitablesolid support is generally insoluble in an aqueous solution.

A subject antibody will in some embodiments comprise a detectable label.Suitable detectable labels include any composition detectable byspectroscopic, photochemical, biochemical, immunochemical, electrical,optical or chemical means. Suitable include, but are not limited to,magnetic beads (e.g. Dynabeads™), fluorescent dyes (e.g., fluoresceinisothiocyanate, texas red, rhodamine, a green fluorescent protein, a redfluorescent protein, a yellow fluorescent protein, and the like),radiolabels (e.g., ³H, ¹²⁵I, ³⁵S, ¹⁴C, or ³²P), enzymes (e.g., horseradish peroxidase, alkaline phosphatase, luciferase, and others commonlyused in an enzyme-linked immunosorbent assay (ELISA)), and colorimetriclabels such as colloidal gold or colored glass or plastic (e.g.polystyrene, polypropylene, latex, etc.) beads.

In some embodiments, a subject antibody comprises a contrast agent or aradioisotope, where the contrast agent or radioisotope is one that issuitable for use in imaging, e.g., imaging procedures carried out onhumans. Non-limiting examples of labels include radioisotope such as¹²³¹I (iodine), ¹⁸F (fluorine), ⁹⁹Tc (technetium), ¹¹¹In (indium), and⁶⁷Ga (gallium), and contrast agent such as gadolinium (Gd), dysprosium,and iron. Radioactive Gd isotopes (¹⁵³Gd) also are available andsuitable for imaging procedures in non-human mammals. A subject antibodycan be labeled using standard techniques. For example, a subjectantibody can be iodinated using chloramine T or1,3,4,6-tetrachloro-3α,6α-diphenylglycouril. For fluorination, fluorineis added to a subject antibody during the synthesis by a fluoride iondisplacement reaction. See, Muller-Gartner, H., TIB Tech., 16:122-130(1998) and Saji, H., Crit. Rev. Ther. Drug Carrier Syst., 16(2):209-244(1999) for a review of synthesis of proteins with such radioisotopes. Asubject antibody can also be labeled with a contrast agent throughstandard techniques. For example, a subject antibody can be labeled withGd by conjugating low molecular Gd chelates such as Gd diethylenetriamine pentaacetic acid (GdDTPA) or Gdtetraazacyclododecanetetraacetic (GdDOTA) to the antibody. See, Caravanet al., Chem. Rev. 99:2293-2352 (1999) and Lauffer et al., J. Magn.Reson. Imaging, 3:11-16 (1985). A subject antibody can be labeled withGd by, for example, conjugating polylysine-Gd chelates to the antibody.See, for example, Curtet et al., Invest. Radiol., 33(10):752-761 (1998).Alternatively, a subject antibody can be labeled with Gd by incubatingparamagnetic polymerized liposomes that include Gd chelator lipid withavidin and biotinylated antibody. See, for example, Sipkins et al.,Nature Med., 4:623-626 (1998).

Suitable fluorescent proteins that can be linked to a subject antibodyinclude, but are not limited to, a green fluorescent protein fromAequoria victoria or a mutant or derivative thereof e.g., as describedin U.S. Pat. Nos. 6,066,476; 6,020,192; 5,985,577; 5,976,796; 5,968,750;5,968,738; 5,958,713; 5,919,445; 5,874,304; e.g., Enhanced GFP, manysuch GFP which are available commercially, e.g., from Clontech, Inc.; ared fluorescent protein; a yellow fluorescent protein; any of a varietyof fluorescent and colored proteins from Anthozoan species, as describedin, e.g., Matz et al. (1999) Nature Biotechnol. 17:969-973; and thelike.

In some embodiments, a subject antibody is conjugated to a therapeutic.Any of the subject antibodies disclosed herein can be used to form anantibody-agent conjugate. The agent can be attached to the N terminus ofthe light chain, the C terminus of the light chain, the N terminus ofthe heavy chain, or the C terminus of the heavy chain. In someembodiments, the agent is attached to the hinge of the antibody or toone or more other sites on the antibody. For a single chain antibody,the agent can be attached to the N or C terminus of the single chainantibody. The agent can be conjugated to the antibody directly or via alinker using techniques known to those skilled in the art. The linkercan be cleavable or non-cleavable. Examples of such therapeutic agents(e.g., for use in therapy) are known to those skilled in the art.

A subject antibody will in some embodiments be linked to (e.g.,covalently or non-covalently linked) a fusion partner, e.g., a ligand;an epitope tag; a peptide; a protein other than an antibody; and thelike. Suitable fusion partners include peptides and polypeptides thatconfer enhanced stability in vivo (e.g., enhanced serum half-life);provide ease of purification, e.g., (His)_(n), e.g., 6His, and the like;provide for secretion of the fusion protein from a cell; provide anepitope tag, e.g., GST, hemagglutinin (HA; e.g., YPYDVPDYA; SEQ IDNO:18), FLAG (e.g., DYKDDDDK; SEQ ID NO:19), c-myc (e.g., EQKLISEEDL;SEQ ID NO:20), and the like; provide a detectable signal, e.g., anenzyme that generates a detectable product (e.g., β-galactosidase,luciferase), or a protein that is itself detectable, e.g., a greenfluorescent protein, a red fluorescent protein, a yellow fluorescentprotein, etc.; provides for multimerization, e.g., a multimerizationdomain such as an Fc portion of an immunoglobulin; and the like.

The fusion can also include an affinity domain, including peptidesequences that can interact with a binding partner, e.g., such as oneimmobilized on a solid support, useful for identification orpurification. Consecutive single amino acids, such as histidine, whenfused to a protein, can be used for one-step purification of the fusionprotein by high affinity binding to a resin column, such as nickelsepharose. Exemplary affinity domains include His5 (HHHHH) (SEQ IDNO:21), His X6 (HHHHHH) (SEQ ID NO:22), c-myc (EQKLISEEDL) (SEQ IDNO:20), Flag (DYKDDDDK) (SEQ ID NO:19), StrepTag (WSHPQFEK) (SEQ IDNO:23), hemagglutinin, e.g., HA Tag (YPYDVPDYA; SEQ ID NO:18),glutathinone-5-transferase (GST), thioredoxin, cellulose binding domain,RYIRS (SEQ ID NO:24), Phe-His-His-Thr (SEQ ID NO:25), chitin bindingdomain, S-peptide, T7 peptide, SH2 domain, C-end RNA tag,WEAAAREACCRECCARA (SEQ ID NO:26), metal binding domains, e.g., zincbinding domains or calcium binding domains such as those fromcalcium-binding proteins, e.g., calmodulin, troponin C, calcineurin B,myosin light chain, recoverin, S-modulin, visinin, VILIP, neurocalcin,hippocalcin, frequenin, caltractin, calpain large-subunit, S100proteins, parvalbumin, calbindin D9K, calbindin D28K, and calretinin,inteins, biotin, streptavidin, MyoD, leucine zipper sequences, andmaltose binding protein.

In some embodiments, an anti-C1s antibody of the present disclosure isformulated with an agent that facilitates crossing the blood-brainbarrier (BBB). In some embodiments, the antibody is fused, directly orthrough a linker, to a compound that promotes the crossing of the BBB.Examples of such a compound include, but are not limited to, a carriermolecule, a peptide, or a protein. A subject antibody will in someembodiments be fused to a polypeptide that binds an endogenous BBBreceptor. Linking a subject antibody to a polypeptide that binds anendogenous BBB receptor facilitates crossing the BBB, e.g., in a subjecttreatment method (see below) involving administration of a subjectantibody to an individual in need thereof. Suitable polypeptides thatbind an endogenous BBB receptor include antibodies, e.g., monoclonalantibodies, or antigen-binding fragments thereof, that specifically bindan endogenous BBB receptor. Suitable endogenous BBB receptors include,but are not limited to, an insulin receptor, a transferrin receptor, aleptin receptor, a lipoprotein receptor, and an insulin-like growthfactor receptor. See, e.g., U.S. Patent Publication No. 2009/0156498.

As an example, a subject anti-C1s antibody can be a bi-specific antibodycomprising a first antigen-binding portion that specifically binds anepitope in a complement C1s protein; and a second antigen-bindingportion that binds an endogenous BBB receptor. For example, in someinstances, a subject anti-C1s antibody is a bi-specific antibodycomprising a first antigen-binding portion that specifically binds anepitope in a C1s protein; and a second antigen-binding portion thatbinds a transferrin receptor.

For example, an anti-C1s antibody of the present disclosure can be fusedto a peptide that facilitates crossing the BBB, the peptide having alength of from about 15 amino acids to about 25 amino acids, andcomprising an amino acid sequence that is at least about 85% amino acidsequence identical to one of the following peptides: Angiopep-1(TFFYGGCRGKRNNFKTEEY) (SEQ ID NO:27); Angiopep-2 (TFFYGGSRGKRNNFKTEEY)(SEQ ID NO:28); cys-Angiopep-2 (CTFFYGGSRGKRNNFKTEEY) (SEQ ID NO:29);Angiopep-2-cys (TFFYGGSRGKRNNFKTEEYC) (SEQ ID NO:30); and an aprotininfragment (TFVYGGCRAKRNNFKS) (SEQ ID NO:31). See, e.g., U.S. PatentPublication Nos. 2011/0288011; and 2009/0016959. A peptide thatfacilitates crossing the BBB can be fused to the N-terminus of ananti-C1s light chain region, to the C-terminus of an anti-C1s lightchain region, to the N-terminus of an anti-C1s heavy chain region, tothe C-terminus of an anti-C1s heavy chain region, to the N-terminus of asubject anti-C1s single-chain antibody, to the C-terminus of a subjectanti-C1s single-chain antibody, etc.

In some embodiments, a subject antibody comprises a polyaminemodification. Polyamine modification of a subject antibody enhancespermeability of the modified antibody at the BBB. A subject antibody canbe modified with polyamines that are either naturally occurring orsynthetic. See, for example, U.S. Pat. No. 5,670,477. Useful naturallyoccurring polyamines include putrescine, spermidine, spermine,1,3-diaminopropane, norspermidine, syn-homospermidine, thermine,thermospermine, caldopentamine, homocaldopentamine, and canavalmine.Putrescine, spermidine and spermine are particularly useful. Syntheticpolyamines are composed of the empirical formula C_(X)H_(Y)N_(Z), can becyclic or acyclic, branched or unbranched, hydrocarbon chains of 3-12carbon atoms that further include 1-6 NR or N(R)₂ moieties, wherein R isH, (C₁-C₄) alkyl, phenyl, or benzyl. Polyamines can be linked to anantibody using any standard crosslinking method.

In some embodiments, a subject antibody is modified to include acarbohydrate moiety, where the carbohydrate moiety can be covalentlylinked to the antibody. In some embodiments, a subject antibody ismodified to include a lipid moiety, where the lipid moiety can becovalently linked to the antibody. Suitable lipid moieties include,e.g., an N-fatty acyl group such as N-lauroyl, N-oleoyl, etc.; a fattyamine such as dodecyl amine, oleoyl amine, etc.; a C3-C16 long-chainaliphatic lipid; and the like. See, e.g., U.S. Pat. No. 6,638,513). Insome embodiments, a subject antibody is incorporated (e.g.,encapsulated) into a liposome.

Methods of Producing a Subject Antibody

A subject antibody can be produced by any known method, e.g.,conventional synthetic methods for protein synthesis; recombinant DNAmethods; etc. In some embodiments, the subject antibody is produced by amethod selected from the group consisting of recombinant production andchemical synthesis.

Where a subject antibody is a single chain polypeptide, it can besynthesized using standard chemical peptide synthesis techniques. Wherea polypeptide is chemically synthesized, the synthesis can proceed vialiquid-phase or solid-phase. Solid phase polypeptide synthesis (SPPS),in which the C-terminal amino acid of the sequence is attached to aninsoluble support followed by sequential addition of the remaining aminoacids in the sequence, is an example of a suitable method for thechemical synthesis of a subject antibody. Various forms of SPPS, such asFmoc and Boc, are available for synthesizing a subject antibody.Techniques for solid phase synthesis are described by Barany andMerrifield, Solid-Phase Peptide Synthesis; pp. 3-284 in The PeptidesAnalysis, Synthesis, Biology. Vol. 2: Special Methods in PeptideSynthesis, Part A., Merrifield, et al. J. Am. Chem. Soc., 85: 2149-2156(1963); Stewart et al., Solid Phase Peptide Synthesis, 2nd ed. PierceChem. Co., Rockford, Ill. (1984); and Ganesan A. 2006 Mini Rev. Med.Chem. 6:3-10 and Camarero J A et al. 2005 Protein Pept Lett. 12:723-8.Briefly, small insoluble, porous beads are treated with functional unitson which peptide chains are built. After repeated cycling ofcoupling/deprotection, the free N-terminal amine of a solid-phaseattached is coupled to a single N-protected amino acid unit. This unitis then deprotected, revealing a new N-terminal amine to which a furtheramino acid can be attached. The peptide remains immobilized on thesolid-phase and undergoes a filtration process before being cleaved off.

Standard recombinant methods can be used for production of a subjectantibody. For example, nucleic acids encoding light and heavy chainvariable regions, optionally linked to constant regions, are insertedinto expression vectors. The light and heavy chains can be cloned in thesame or different expression vectors. The DNA segments encodingimmunoglobulin chains are operably linked to control sequences in theexpression vector(s) that ensure the expression of immunoglobulinpolypeptides. Expression control sequences include, but are not limitedto, promoters (e.g., naturally-associated or heterologous promoters),signal sequences, enhancer elements, repressor elements, andtranscription termination sequences. The expression control sequencescan be eukaryotic promoter systems in vectors capable of transforming ortransfecting eukaryotic host cells (e.g., COS or CHO cells). Once thevector has been incorporated into the appropriate host, the host ismaintained under conditions suitable for high level expression of thenucleotide sequences, and the collection and purification of theantibodies.

Because of the degeneracy of the code, a variety of nucleic acidsequences can encode each immunoglobulin amino acid sequence. Thedesired nucleic acid sequences can be produced by de novo solid-phaseDNA synthesis or by polymerase chain reaction (PCR) mutagenesis of anearlier prepared variant of the desired polynucleotide.Oligonucleotide-mediated mutagenesis is an example of a suitable methodfor preparing substitution, deletion and insertion variants of targetpolypeptide DNA. See Adelman et al., DNA 2:183 (1983). Briefly, thetarget polypeptide DNA is altered by hybridizing an oligonucleotideencoding the desired mutation to a single-stranded DNA template. Afterhybridization, a DNA polymerase is used to synthesize an entire secondcomplementary strand of the template that incorporates theoligonucleotide primer, and encodes the selected alteration in thetarget polypeptide DNA.

Suitable expression vectors are typically replicable in the hostorganisms either as episomes or as an integral part of the hostchromosomal DNA. Commonly, expression vectors contain selection markers(e.g., ampicillin-resistance, hygromycin-resistance, tetracyclineresistance, kanamycin resistance or neomycin resistance) to permitdetection of those cells transformed with the desired DNA sequences.

Escherichia coli is an example of a prokaryotic host cell that can beused for cloning a subject antibody-encoding polynucleotide. Othermicrobial hosts suitable for use include bacilli, such as Bacillussubtilis, and other enterobacteriaceae, such as Salmonella, Serratia,and various Pseudomonas species. In these prokaryotic hosts, one canalso make expression vectors, which will typically contain expressioncontrol sequences compatible with the host cell (e.g., an origin ofreplication). In addition, any number of a variety of well-knownpromoters will be present, such as the lactose promoter system, atryptophan (trp) promoter system, a beta-lactamase promoter system, or apromoter system from phage lambda. The promoters will typically controlexpression, optionally with an operator sequence, and have ribosomebinding site sequences and the like, for initiating and completingtranscription and translation.

Other microbes, such as yeast, are also useful for expression.Saccharomyces (e.g., S. cerevisiae) and Pichia are examples of suitableyeast host cells, with suitable vectors having expression controlsequences (e.g., promoters), an origin of replication, terminationsequences and the like as desired. Typical promoters include3-phosphoglycerate kinase and other glycolytic enzymes. Inducible yeastpromoters include, among others, promoters from alcohol dehydrogenase,isocytochrome C, and enzymes responsible for maltose and galactoseutilization.

In addition to microorganisms, mammalian cells (e.g., mammalian cellsgrown in in vitro cell culture) can also be used to express and producean anti-C1s antibody of the present disclosure (e.g., polynucleotidesencoding a subject anti-C1s antibody). See Winnacker, From Genes toClones, VCH Publishers, N.Y., N.Y. (1987). Suitable mammalian host cellsinclude CHO cell lines, various Cos cell lines, HeLa cells, myeloma celllines, and transformed B-cells or hybridomas. Expression vectors forthese cells can include expression control sequences, such as an originof replication, a promoter, and an enhancer (Queen et al., Immunol. Rev.89:49 (1986)), and necessary processing information sites, such asribosome binding sites, RNA splice sites, polyadenylation sites, andtranscriptional terminator sequences. Examples of suitable expressioncontrol sequences are promoters derived from immunoglobulin genes, SV40,adenovirus, bovine papilloma virus, cytomegalovirus and the like. See Coet al., J. Immunol. 148:1149 (1992).

Once synthesized (either chemically or recombinantly), the wholeantibodies, their dimers, individual light and heavy chains, or otherforms of a subject antibody (e.g., scFv, etc.) can be purified accordingto standard procedures of the art, including ammonium sulfateprecipitation, affinity columns, column chromatography, high performanceliquid chromatography (HPLC) purification, gel electrophoresis, and thelike (see generally Scopes, Protein Purification (Springer-Verlag, N.Y.,(1982)). A subject antibody can be substantially pure, e.g., at leastabout 80% to 85% pure, at least about 85% to 90% pure, at least about90% to 95% pure, or 98% to 99%, or more, pure, e.g., free fromcontaminants such as cell debris, macromolecules other than a subjectantibody, etc.

Compositions

The present disclosure provides a composition comprising a subjectantibody. A subject antibody composition can comprise, in addition to asubject antibody, one or more of: a salt, e.g., NaCl, MgCl₂, KCl, MgSO₄,etc.; a buffering agent, e.g., a Tris buffer,N-(2-Hydroxyethyl)piperazine-N′-(2-ethanesulfonic acid) (HEPES),2-(N-Morpholino)ethanesulfonic acid (MES),2-(N-Morpholino)ethanesulfonic acid sodium salt (MES),3-(N-Morpholino)propanesulfonic acid (MOPS),N-tris[Hydroxymethyl]methyl-3-aminopropanesulfonic acid (TAPS), etc.; asolubilizing agent; a detergent, e.g., a non-ionic detergent such asTween-20, etc.; a protease inhibitor; glycerol; and the like.

Nucleic Acid Molecules, Expression Vectors, and Host Cells

The present disclosure provides nucleic acid molecules comprisingnucleotide sequences encoding a subject anti-C1s antibody.

In some embodiments, a nucleic acid molecule of the present disclosureencodes a subject anti-C1s antibody comprising a light chain variableregion that is at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98% or 99% amino acid sequence identical to theamino acid sequence set forth in SEQ ID NO:7. In some embodiments, anucleic acid molecule of the present disclosure encodes a subjectanti-C1s antibody comprising a light chain variable region comprisingthe amino acid sequence set forth in SEQ ID NO:7.

In some embodiments, a nucleic acid molecule of the present disclosureencodes a subject anti-C1s antibody comprising a heavy chain variableregion that is at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98% or 99% amino acid sequence identical to theamino acid sequence set forth in SEQ ID NO:8. In some embodiments, anucleic acid molecule of the present disclosure encodes a subjectanti-C1s antibody comprising a heavy chain variable region comprisingthe amino acid sequence set forth in SEQ ID NO:8.

In some embodiments, a nucleic acid molecule of the present disclosureencodes a subject anti-C1s antibody comprising a light chain variableregion comprising a CDR-L1, a CDR-L2, and a CDR-L3 of SEQ ID NO:1, SEQID NO:2, and SEQ ID NO:3, respectively.

In some embodiments, a nucleic acid molecule of the present disclosureencodes a subject anti-C1s antibody comprising a heavy chain variableregion comprising a CDR-H1, a CDR-H2, and a CDR-H3 of SEQ ID NO:4, SEQID NO:5, and SEQ ID NO:6, respectively.

In some embodiments, a nucleic acid molecule of the present disclosureencodes a subject anti-C1s antibody comprising a light chain variableregion that is at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98% or 99% amino acid sequence identical to theamino acid sequence set forth in SEQ ID NO:37. In some embodiments, anucleic acid molecule of the present disclosure encodes a subjectanti-C1s antibody comprising a light chain variable region comprisingthe amino acid sequence set forth in SEQ ID NO:37.

In some embodiments, a nucleic acid molecule of the present disclosureencodes a subject anti-C1s antibody comprising a heavy chain variableregion that is at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98% or 99% amino acid sequence identical to theamino acid sequence set forth in SEQ ID NO:38. In some embodiments, anucleic acid molecule of the present disclosure encodes a subjectanti-C1s antibody comprising a heavy chain variable region comprisingthe amino acid sequence set forth in SEQ ID NO:38.

In some embodiments, a nucleic acid molecule of the present disclosureencodes a subject anti-C1s antibody comprising a light chain variableregion comprising a CDR-L1, a CDR-L2, and a CDR-L3 of SEQ ID NO:32, SEQID NO:33, and SEQ ID NO:3, respectively.

In some embodiments, a nucleic acid molecule of the present disclosureencodes a subject anti-C1s antibody comprising a heavy chain variableregion comprising a CDR-H1, a CDR-H2, and a CDR-H3 of SEQ ID NO:34, SEQID NO:35, and SEQ ID NO:36, respectively.

In some embodiments, a nucleic acid molecule of the present disclosureencodes a subject anti-C1s antibody comprising a light chain variableregion and a heavy chain variable region.

A nucleic acid molecule encoding a subject antibody can be operablylinked to one or more regulatory elements, such as a promoter andenhancer, that allow expression of the nucleotide sequence in theintended target cells (e.g., a cell that is genetically modified tosynthesize the encoded antibody).

Suitable promoter and enhancer elements are known in the art. Suitablepromoters for use in prokaryotic host cells include, but are not limitedto, a bacteriophage T7 RNA polymerase promoter; a T3 promoter; a T5promoter; a lambda P promoter; a trp promoter; a lac operon promoter; ahybrid promoter, e.g., a lac/tac hybrid promoter, a tac/trc hybridpromoter, a trp/lac promoter, a T7/lac promoter; a trc promoter; a tacpromoter, and the like; a gpt promoter; an araBAD promoter; in vivoregulated promoters, such as an ssaG promoter or a related promoter(see, e.g., U.S. Patent Publication No. 20040131637), a pagC promoter(Pulkkinen and Miller, J. Bacteriol., 1991: 173(1): 86-93;Alpuche-Aranda et al., PNAS, 1992; 89(21): 10079-83), a nirB promoter(Harborne et al. (1992) Mol. Micro. 6:2805-2813), and the like (see,e.g., Dunstan et al. (1999) Infect. Immun. 67:5133-5141; McKelvie et al.(2004) Vaccine 22:3243-3255; and Chatfield et al. (1992) Biotechnol.10:888-892); a sigma70 promoter, e.g., a consensus sigma70 promoter(see, e.g., GenBank Accession Nos. AX798980, AX798961, and AX798183); astationary phase promoter, e.g., a dps promoter, an spy promoter, andthe like; a promoter derived from the pathogenicity island SPI-2 (see,e.g., WO96/17951); an actA promoter (see, e.g., Shetron-Rama et al.(2002) Infect. Immun. 70:1087-1096); an rpsM promoter (see, e.g.,Valdivia and Falkow (1996). Mol. Microbiol. 22:367); a tet promoter(see, e.g., Hillen, W. and Wissmann, A. (1989) In Saenger, W. andHeinemann, U. (eds), Topics in Molecular and Structural Biology,Protein-Nucleic Acid Interaction. Macmillan, London, UK, Vol. 10, pp.143-162); an SP6 promoter (see, e.g., Melton et al. (1984) Nucl. AcidsRes. 12:7035); and the like. Suitable strong promoters for use inprokaryotes such as Escherichia coli include, but are not limited toTrc, Tac, T5, T7, and P_(Lambda). Non-limiting examples of operators foruse in bacterial host cells include a lactose promoter operator (Ladrepressor protein changes conformation when contacted with lactose,thereby preventing the Lad repressor protein from binding the operator),a tryptophan promoter operator (when complexed with tryptophan, TrpRrepressor protein has a conformation that binds the operator; in theabsence of tryptophan, the TrpR repressor protein has a conformationthat does not bind the operator), and a tac promoter operator (see, forexample, deBoer et al. (1983) Proc. Natl. Acad. Sci. U.S.A. 80:21-25).

In some embodiments, e.g., for expression in a yeast cell, a suitablepromoter is a constitutive promoter such as an ADH1 promoter, a PGK1promoter, an ENO promoter, a PYK1 promoter and the like; or aregulatable promoter such as a GAL1 promoter, a GAL10 promoter, an ADH2promoter, a PHOS promoter, a CUP1 promoter, a GAL7 promoter, a MET25promoter, a MET3 promoter, a CYC1 promoter, a HIS3 promoter, an ADH1promoter, a PGK promoter, a GAPDH promoter, an ADC1 promoter, a TRP1promoter, a URA3 promoter, a LEU2 promoter, an ENO promoter, a TP1promoter, and AOX1 (e.g., for use in Pichia).

For expression in a eukaryotic cell, suitable promoters include, but arenot limited to, light and/or heavy chain immunoglobulin gene promoterand enhancer elements; cytomegalovirus immediate early promoter; herpessimplex virus thymidine kinase promoter; early and late SV40 promoters;promoter present in long terminal repeats from a retrovirus; mousemetallothionein-I promoter; and various art-known tissue specificpromoters.

Selection of the appropriate vector and promoter is well within thelevel of ordinary skill in the art.

A nucleic acid molecule encoding a subject antibody can be present in anexpression vector and/or a cloning vector. The present disclosureprovides a recombinant vector, which comprises a nucleic acid moleculeencoding a subject antibody in a cloning vector. The present disclosurealso provides a recombinant molecule, which comprises a nucleic acidmolecule encoding a subject antibody operatively linked to appropriateregulatory sequence(s) in an expression vector to ensure expression ofthe encoded antibody. Where a subject antibody comprises two separatepolypeptides, nucleic acid molecules encoding the two polypeptides canbe cloned in the same or separate vectors to form one or morerecombinant molecules. A recombinant molecule can include a selectablemarker, an origin of replication, and other features that provide forreplication and/or maintenance of the recombinant molecule.

Large numbers of suitable vectors and promoters are known to those ofskill in the art; many are commercially available for generating asubject recombinant molecule. The following vectors are provided by wayof example. Bacterial: pBs, phagescript, PsiX174, pBluescript SK, pBsKS, pNH8a, pNH16a, pNH18a, pNH46a (Stratagene, La Jolla, Calif., USA);pTrc99A, pKK223-3, pKK233-3, pDR540, and pRIT5 (Pharmacia, Uppsala,Sweden). Eukaryotic: pWLneo, pSV2cat, pOG44, PXR1, pSG (Stratagene)pSVK3, pBPV, pMSG and pSVL (Pharmacia).

Expression vectors generally have convenient restriction sites locatednear the promoter sequence to provide for the insertion of nucleic acidsequences encoding heterologous proteins. A selectable marker operativein the expression host can be present. Suitable expression vectorsinclude, but are not limited to, viral vectors. Examples of viralvectors include, but are not limited to, viral vectors based on:vaccinia virus; poliovirus; adenovirus (see, e.g., Li et al., InvestOpthalmol V is Sci 35:2543 2549, 1994; Borras et al., Gene Ther 6:515524, 1999; L1 and Davidson, PNAS 92:7700 7704, 1995; Sakamoto et al., HGene Ther 5:1088 1097, 1999; WO 94/12649, WO 93/03769; WO 93/19191; WO94/28938; WO 95/11984 and WO 95/00655); adeno-associated virus (see,e.g., Ali et al., Hum Gene Ther 9:8186, 1998, Flannery et al., PNAS94:6916 6921, 1997; Bennett et al., Invest Opthalmol V is Sci 38:28572863, 1997; Jomary et al., Gene Ther 4:683 690, 1997, Rolling et al.,Hum Gene Ther 10:641648, 1999; Ali et al., Hum Mol Genet. 5:591594,1996; Srivastava in WO 93/09239, Samulski et al., J. Vir. (1989)63:3822-3828; Mendelson et al., Virol. (1988) 166:154-165; and Flotte etal., PNAS (1993) 90:10613-10617); SV40; herpes simplex virus; aretroviral vector (e.g., Murine Leukemia Virus, spleen necrosis virus,and vectors derived from retroviruses such as Rous Sarcoma Virus, HarveySarcoma Virus, avian leukosis virus, human immunodeficiency virus (see,e.g., Miyoshi et al., PNAS 94:10319 23, 1997; Takahashi et al., J Virol73:7812 7816, 1999), myeloproliferative sarcoma virus, and mammary tumorvirus); and the like.

As noted above, a subject nucleic acid molecule comprises a nucleotidesequence encoding an anti-C1s antibody of the present disclosure. Insome embodiments, a subject nucleic acid molecule comprises a nucleotidesequence encoding heavy- and light-chain CDRs of a subject IPN003antibody. In some embodiments, a subject nucleic acid molecule comprisesa nucleotide sequence encoding heavy- and light-chain CDRs of a subjectantibody, where the CDR-encoding sequences are interspersed withFR-encoding nucleotide sequences. In some embodiments, the FR-encodingnucleotide sequences are human FR-encoding nucleotide sequences.

Host Cells

The present disclosure provides isolated genetically modified host cells(e.g., in vitro cells) that are genetically modified with a subjectnucleic acid molecule. In some embodiments, a subject isolatedgenetically modified host cell can produce a subject antibody. Such acell is referred to as a recombinant cell. A recombinant cell comprisesa recombinant molecule encoding a subject antibody.

Suitable host cells include eukaryotic host cells, such as a mammaliancell, an insect host cell, a yeast cell; and prokaryotic cells, such asa bacterial cell. Introduction of a subject nucleic acid into the hostcell can be effected, for example by calcium phosphate precipitation,DEAE dextran mediated transfection, liposome-mediated transfection,electroporation, or other known method.

Suitable mammalian cells include primary cells and immortalized celllines. Suitable mammalian cell lines include human cell lines, non-humanprimate cell lines, rodent (e.g., mouse, rat) cell lines, and the like.Suitable mammalian cell lines include, but are not limited to, HeLacells (e.g., American Type Culture Collection (ATCC) No. CCL-2), CHOcells (e.g., ATCC Nos. CRL9618, CCL61, CRL9096), 293 cells (e.g., ATCCNo. CRL-1573), Vero cells, NIH 3T3 cells (e.g., ATCC No. CRL-1658),Huh-7 cells, BHK cells (e.g., ATCC No. CCL10), PC12 cells (ATCC No.CRL1721), COS cells, COS-7 cells (ATCC No. CRL1651), RAT1 cells, mouse Lcells (ATCC No. CCLI.3), human embryonic kidney (HEK) cells (ATCC No.CRL1573), HLHepG2 cells, and the like. In some cases, the cells are HEKcells. In some cases, the cells are CHO cells, e.g., CHO-K1 cells (ATCCNo. CCL-61), CHO-M cells, CHO-DG44 cells (ATCC No. PTA-3356), and thelike. In some embodiments, the host cell is a COS cell. In someembodiments, the host cell is a 293 cell. In some embodiments, the hostcell is a CHO cell.

Suitable yeast cells include, but are not limited to, Pichia pastoris,Pichia finlandica, Pichia trehalophila, Pichia koclamae, Pichiamembranaefaciens, Pichia opuntiae, Pichia thermotolerans, Pichiasalictaria, Pichia guercuum, Pichia ptjperi, Pichia stiptis, Pichiamethanolica, Pichia sp., Saccharomyces cerevisiae, Saccharomyces sp.,Hansenula polymorpha, Kluyveromyces sp., Kluyveromyces lactis, Candidaalbicans, Aspergillus nidulans, Aspergillus niger, Aspergillus oryzae,Trichoderma reesei, Chrysosporium lucknowense, Fusarium sp., Fusariumgramineum, Fusarium venenatum, Neurospora crassa, Chlamydomonasreinhardtii, and the like. In some embodiments, the host cell is aSaccharomyces. In some embodiments, the host cell is a Pichia.

Suitable prokaryotic cells include, but are not limited to, any of avariety of laboratory strains of Escherichia coli, Bacillus (e.g., B.subtilis), Lactobacillus sp., and the like. See, e.g., Carrier et al.(1992) J. Immunol. 148:1176-1181; U.S. Pat. No. 6,447,784; and Sizemoreet al. (1995) Science 270:299-302. Typically, the laboratory strain isone that is non-pathogenic. In some embodiments, the host cell isEscherichia coli. In some embodiments, the host cell is Bacillussubtilis.

Pharmaceutical Compositions

The present disclosure provides compositions, including pharmaceuticalcompositions comprising a subject antibody. In general, a pharmaceuticalcomposition, also referred to herein as a formulation, comprises aneffective amount of a subject antibody. An “effective amount” means adosage sufficient to produce a desired result, e.g., reduction in anadverse symptom associated with a complement-mediated disease ordisorder, amelioration of a symptom of a complement-mediated disease ordisorder, slowing progression of a complement-mediated disease ordisorder, etc. Generally, the desired result is at least a reduction ina symptom of a complement-mediated disease or disorder, as compared to acontrol. In some embodiments, a subject antibody is formulated and/ormodified to enable the antibody to cross the blood-brain barrier. Insome embodiments, a subject antibody is delivered in such a manner as toavoid the blood-brain barrier. In some embodiments, an anti-C1s antibodyof the present disclosure is formulated with an agent that facilitatescrossing the blood-brain barrier. In some embodiments, the subjectantibody is fused, directly or through a linker, to a compound thatpromotes the crossing of the blood-brain barrier.

Formulations

In the subject methods, a subject antibody can be administered to thehost using any convenient means capable of resulting in the desiredtherapeutic effect or diagnostic effect. Thus, the agent can beincorporated into a variety of formulations for therapeuticadministration. More particularly, a subject antibody can be formulatedinto pharmaceutical compositions by combination with appropriate,pharmaceutically acceptable carriers, pharmaceutically acceptablediluents, or other pharmaceutically acceptable excipients and can beformulated into preparations in solid, semi-solid, liquid or gaseousforms, such as tablets, capsules, powders, granules, ointments,solutions, suppositories, injections, inhalants and aerosols. In someembodiments, a pharmaceutical composition comprises a subject antibodyand a pharmaceutically acceptable excipient.

In pharmaceutical dosage forms, a subject antibody can be administeredin the form of their pharmaceutically acceptable salts, or they can alsobe used alone or in appropriate association, as well as in combination,with other pharmaceutically active compounds. The following methods andexcipients are merely exemplary and are in no way limiting.

For oral preparations, a subject antibody can be used alone or incombination with appropriate additives to make tablets, powders,granules or capsules, for example, with conventional additives, such aslactose, mannitol, corn starch or potato starch; with binders, such ascrystalline cellulose, cellulose derivatives, acacia, corn starch orgelatins; with disintegrators, such as corn starch, potato starch orsodium carboxymethylcellulose; with lubricants, such as talc ormagnesium stearate; and if desired, with diluents, buffering agents,moistening agents, preservatives and flavoring agents.

A subject antibody can be formulated into preparations for injection bydissolving, suspending or emulsifying the antibody in an aqueous ornonaqueous solvent, such as vegetable or other similar oils, propyleneglycol, synthetic aliphatic acid glycerides, injectable organic esters(e.g., ethyl oleate), esters of higher aliphatic acids or propyleneglycol; and if desired, with conventional additives such assolubilizers, isotonic agents, suspending agents, emulsifying agents,stabilizers and preservatives. Parenteral vehicles include sodiumchloride solution, Ringer's dextrose, dextrose and sodium chloride,lactated Ringer's, or fixed oils. Intravenous vehicles include fluid andnutrient replenishers, electrolyte replenishers (such as those based onRinger's dextrose), and the like. Furthermore, the pharmaceuticalcomposition of the present disclosure can comprise further agents suchas dopamine or psychopharmacologic drugs, depending on the intended useof the pharmaceutical composition.

Pharmaceutical compositions comprising a subject antibody are preparedby mixing a subject antibody having the desired degree of purity withoptional physiologically acceptable carriers, other excipients,stabilizers, surfactants, buffers and/or tonicity agents. Acceptablecarriers, other excipients and/or stabilizers are nontoxic to recipientsat the dosages and concentrations employed, and include buffers such asphosphate, citrate, and other organic acids; antioxidants includingascorbic acid, glutathione, cysteine, methionine and citric acid;preservatives (such as ethanol, benzyl alcohol, phenol, m-cresol,p-chlor-m-cresol, methyl or propyl parabens, benzalkonium chloride, orcombinations thereof); amino acids such as arginine, glycine, ornithine,lysine, histidine, glutamic acid, aspartic acid, isoleucine, leucine,alanine, phenylalanine, tyrosine, tryptophan, methionine, serine,proline and combinations thereof; monosaccharides, disaccharides andother carbohydrates; low molecular weight (less than about 10 residues)polypeptides; proteins, such as gelatin or serum albumin; chelatingagents such as EDTA; sugars such as trehalose, sucrose, lactose,glucose, mannose, maltose, galactose, fructose, sorbose, raffinose,glucosamine, N-methylglucosamine, galactosamine, and neuraminic acid;and/or non-ionic surfactants such as Tween, Brij Pluronics, Triton-X, orpolyethylene glycol (PEG).

The pharmaceutical composition can be in a liquid form, a lyophilizedform or a liquid form reconstituted from a lyophilized form, wherein thelyophilized preparation is to be reconstituted with a sterile solutionprior to administration. The standard procedure for reconstituting alyophilized composition is to add back a volume of pure water (typicallyequivalent to the volume removed during lyophilization); howeversolutions comprising antibacterial agents can be used for the productionof pharmaceutical compositions for parenteral administration; see alsoChen (1992) Drug Dev Ind Pharm 18, 1311-54.

Exemplary antibody concentrations in a subject pharmaceuticalcomposition can range from about 1 mg/mL to about 200 mg/mL or fromabout 50 mg/mL to about 200 mg/mL, or from about 150 mg/mL to about 200mg/mL.

An aqueous formulation of the antibody can be prepared in a pH-bufferedsolution, e.g., at pH ranging from about 4.0 to about 7.0, or from about5.0 to about 6.0, or alternatively about 5.5. Examples of buffers thatare suitable for a pH within this range include phosphate-, histidine-,citrate-, succinate-, acetate-buffers and other organic acid buffers.The buffer concentration can be from about 1 mM to about 100 mM, or fromabout 5 mM to about 50 mM, depending, e.g., on the buffer and thedesired tonicity of the formulation.

A tonicity agent can be included in the antibody formulation to modulatethe tonicity of the formulation. Exemplary tonicity agents includesodium chloride, potassium chloride, glycerin and any component from thegroup of amino acids, sugars as well as combinations thereof. In someembodiments, the aqueous formulation is isotonic, although hypertonic orhypotonic solutions can be suitable. The term “isotonic” denotes asolution having the same tonicity as some other solution with which itis compared, such as a physiological salt solution or serum. Tonicityagents can be used in an amount of about 5 mM to about 350 mM, e.g., inan amount of 100 mM to 350 nM.

A surfactant can also be added to the antibody formulation to reduceaggregation of the formulated antibody and/or minimize the formation ofparticulates in the formulation and/or reduce adsorption. Exemplarysurfactants include polyoxyethylensorbitan fatty acid esters (Tween),polyoxyethylene alkyl ethers (Brij), alkylphenylpolyoxyethylene ethers(Triton-X), polyoxyethylene-polyoxypropylene copolymer (Poloxamer,Pluronic), and sodium dodecyl sulfate (SDS). Examples of suitablepolyoxyethylenesorbitan-fatty acid esters are polysorbate 20, (soldunder the trademark Tween 20™) and polysorbate 80 (sold under thetrademark Tween 80™). Examples of suitable polyethylene-polypropylenecopolymers are those sold under the names Pluronic® F68 or Poloxamer188™. Examples of suitable Polyoxyethylene alkyl ethers are those soldunder the trademark Brij™. Exemplary concentrations of surfactant canrange from about 0.001% to about 1% w/v.

A lyoprotectant can also be added in order to protect the labile activeingredient (e.g. a protein) against destabilizing conditions during thelyophilization process. For example, known lyoprotectants include sugars(including glucose and sucrose); polyols (including mannitol, sorbitoland glycerol); and amino acids (including alanine, glycine and glutamicacid). Lyoprotectants can be included in an amount of about 10 mM to 500nM.

In some embodiments, a subject formulation includes a subject antibody,and one or more of the above-identified agents (e.g., a surfactant, abuffer, a stabilizer, a tonicity agent) and is essentially free of oneor more preservatives, such as ethanol, benzyl alcohol, phenol,m-cresol, p-chlor-m-cresol, methyl or propyl parabens, benzalkoniumchloride, and combinations thereof. In other embodiments, a preservativeis included in the formulation, e.g., at concentrations ranging fromabout 0.001 to about 2% (w/v).

For example, a subject formulation can be a liquid or lyophilizedformulation suitable for parenteral administration, and can comprise:about 1 mg/mL to about 200 mg/mL of a subject antibody; about 0.001% toabout 1% of at least one surfactant; about 1 mM to about 100 mM of abuffer; optionally about 10 mM to about 500 mM of a stabilizer; andabout 5 mM to about 305 mM of a tonicity agent; and has a pH of about4.0 to about 7.0.

As another example, a subject parenteral formulation is a liquid orlyophilized formulation comprising: about 1 mg/mL to about 200 mg/mL ofa subject antibody; 0.04% Tween 20 w/v; 20 mM L-histidine; and 250 mMSucrose; and has a pH of 5.5.

As another example, a subject parenteral formulation comprises alyophilized formulation comprising: 1) 15 mg/mL of a subject antibody;0.04% Tween 20 w/v; 20 mM L-histidine; and 250 mM sucrose; and has a pHof 5.5; or 2) 75 mg/mL of a subject antibody; 0.04% Tween 20 w/v; 20 mML-histidine; and 250 mM sucrose; and has a pH of 5.5; or 3) 75 mg/mL ofa subject antibody; 0.02% Tween 20 w/v; 20 mM L-histidine; and 250 mMsucrose; and has a pH of 5.5; or 4) 75 mg/mL of a subject antibody;0.04% Tween 20 w/v; 20 mM L-histidine; and 250 mM trehalose; and has apH of 5.5; or 5) 75 mg/mL of a subject antibody; 0.02% Tween 20 w/v; 20mM L-histidine; and 250 mM trehalose; and has a pH of 5.5.

As another example, a subject parenteral formulation is a liquidformulation comprising: 1) 7.5 mg/mL of a subject antibody; 0.02% Tween20 w/v; 120 mM L-histidine; and 250 125 mM sucrose; and has a pH of 5.5;or 2) 37.5 mg/mL of a subject antibody; 0.02% Tween 20 w/v; 10 mML-histidine; and 125 mM sucrose; and has a pH of 5.5; or 3) 37.5 mg/mLof a subject antibody; 0.01% Tween 20 w/v; 10 mM L-histidine; and 125 mMsucrose; and has a pH of 5.5; or 4) 37.5 mg/mL of a subject antibody;0.02% Tween 20 w/v; 10 mM L-histidine; 125 mM trehalose; and has a pH of5.5; or 5) 37.5 mg/mL of a subject antibody; 0.01% Tween 20 w/v; 10 mML-histidine; and 125 mM trehalose; and has a pH of 5.5; or 6) 5 mg/mL ofa subject antibody; 0.02% Tween 20 w/v; 20 mM L-histidine; and 250 mMtrehalose; and has a pH of 5.5; or 7) 75 mg/mL of a subject antibody;0.02% Tween 20 w/v; 20 mM L-histidine; and 250 mM mannitol; and has a pHof 5.5; or 8) 75 mg/mL of a subject antibody; 0.02% Tween 20 w/v; 20 mML histidine; and 140 mM sodium chloride; and has a pH of 5.5; or 9) 150mg/mL of a subject antibody; 0.02% Tween 20 w/v; 20 mM L-histidine; and250 mM trehalose; and has a pH of 5.5; or 10) 150 mg/mL of a subjectantibody; 0.02% Tween 20 w/v; 20 mM L-histidine; and 250 mM mannitol;and has a pH of 5.5; or 11) 150 mg/mL of a subject antibody; 0.02% Tween20 w/v; 20 mM L-histidine; and 140 mM sodium chloride; and has a pH of5.5; or 12) 10 mg/mL of a subject antibody; 0.01% Tween 20 w/v; 20 mML-histidine; and 40 mM sodium chloride; and has a pH of 5.5.

A subject antibody can be utilized in aerosol formulation to beadministered via inhalation. A subject antibody can be formulated intopressurized acceptable propellants such as dichlorodifluoromethane,propane, nitrogen and the like. Aerosol formulations such as nasal sprayformulations include purified aqueous or other solutions of the activeagent with preservative agents and isotonic agents. Such formulationsare adjusted to a pH and isotonic state compatible with the nasal mucousmembranes.

Furthermore, a subject antibody can be made into suppositories by mixingwith a variety of bases such as emulsifying bases or water-solublebases. A subject antibody can be administered rectally via asuppository. The suppository can include vehicles such as cocoa butter,carbowaxes and polyethylene glycols, which melt at body temperature, yetare solidified at room temperature.

Unit dosage forms for oral or rectal administration such as syrups,elixirs, and suspensions can be provided wherein each dosage unit, forexample, teaspoonful, tablespoonful, tablet or suppository, contains apredetermined amount of the composition. Similarly, unit dosage formsfor injection or intravenous administration can comprise a subjectantibody in a composition as a solution in sterile water, normal salineor another pharmaceutically acceptable carrier.

The term “unit dosage form,” as used herein, refers to physicallydiscrete units suitable as unitary dosages for human and animalsubjects, each unit containing a predetermined quantity of an anti-C1santibody of the present disclosure, calculated in an amount sufficientto produce the desired effect in association with a pharmaceuticallyacceptable diluent, carrier or vehicle. The specifications for a subjectantibody can depend on the particular antibody employed and the effectto be achieved, and the pharmacodynamics associated with each antibodyin the host.

Other modes of administration will also find use with a method of thepresent disclosure. For instance, a subject antibody can be formulatedin suppositories and, in some cases, aerosol and intranasalcompositions. For suppositories, the vehicle composition will includetraditional binders and carriers such as, polyalkylene glycols, ortriglycerides. Such suppositories can be formed from mixtures containingthe active ingredient in the range of about 0.5% to about 10% (w/w),e.g., about 1% to about 2%.

Intranasal formulations will usually include vehicles that neither causeirritation to the nasal mucosa nor significantly disturb ciliaryfunction. Diluents such as water, aqueous saline or other knownsubstances can be employed. The nasal formulations can also containpreservatives such as, but not limited to, chlorobutanol andbenzalkonium chloride. A surfactant can be present to enhance absorptionof the subject antibody by the nasal mucosa.

A subject antibody can be administered as an injectable formulation.Typically, injectable compositions are prepared as liquid solutions orsuspensions; solid forms suitable for solution in, or suspension in,liquid vehicles prior to injection can also be prepared. The preparationcan also be emulsified or the antibody encapsulated in liposomevehicles.

Suitable excipient vehicles are, for example, water, saline, dextrose,glycerol, ethanol, or the like, and combinations thereof. In addition,if desired, the vehicle can contain minor amounts of auxiliarysubstances such as wetting or emulsifying agents or pH buffering agents.Actual methods of preparing such dosage forms are known, or will beapparent, to those skilled in the art. See, e.g., Remington'sPharmaceutical Sciences, Mack Publishing Company, Easton, Pa., 17thedition, 1985. The composition or formulation to be administered will,in any event, contain a quantity of a subject antibody adequate toachieve the desired state in the subject being treated.

The pharmaceutically acceptable excipients, such as vehicles, adjuvants,carriers or diluents, are readily available to the public. Moreover,pharmaceutically acceptable auxiliary substances, such as pH adjustingand buffering agents, tonicity adjusting agents, stabilizers, wettingagents and the like, are readily available to the public.

In some embodiments, a subject antibody is formulated in a controlledrelease formulation. Sustained-release preparations can be preparedusing methods well known in the art. Suitable examples ofsustained-release preparations include semipermeable matrices of solidhydrophobic polymers containing the antibody in which the matrices arein the form of shaped articles, e.g. films or microcapsules. Examples ofsustained-release matrices include polyesters, copolymers of L-glutamicacid and ethyl-L-glutamate, non-degradable ethylene-vinyl acetate,hydrogels, polylactides, degradable lactic acid-glycolic acid copolymersand poly-D-(−)-3-hydroxybutyric acid. Possible loss of biologicalactivity and possible changes in immunogenicity of antibodies comprisedin sustained-release preparations can be prevented by using appropriateadditives, by controlling moisture content and by developing specificpolymer matrix compositions.

Controlled release within the scope of the present disclosure can betaken to mean any one of a number of extended release dosage forms. Thefollowing terms can be considered to be substantially equivalent tocontrolled release, for the purposes of the present disclosure:continuous release, controlled release, delayed release, depot, extendedrelease, gradual release, immediate release, long-term release,programmed release, prolonged release, proportionate release, protractedrelease, repository, retard, slow release, spaced release, sustainedrelease, time coat, timed release, delayed action, extended action,layered-time action, long acting, prolonged action, repeated action,slowing acting, sustained action, and sustained-action medications.Further discussions of these terms can be found in Lesczek Krowczynski,Extended-Release Dosage Forms, 1987 (CRC Press, Inc.).

The various controlled release technologies cover a very broad spectrumof drug dosage forms. Controlled release technologies include, but arenot limited to physical systems and chemical systems.

Physical systems include, but are not limited to, reservoir systems withrate-controlling membranes, such as microencapsulation,macroencapsulation, and membrane systems; reservoir systems withoutrate-controlling membranes, such as hollow fibers, ultra microporouscellulose triacetate, and porous polymeric substrates and foams;monolithic systems, including those systems physically dissolved innon-porous, polymeric, or elastomeric matrices (e.g., nonerodible,erodible, environmental agent ingression, and degradable), and materialsphysically dispersed in non-porous, polymeric, or elastomeric matrices(e.g., nonerodible, erodible, environmental agent ingression, anddegradable); laminated structures, including reservoir layers chemicallysimilar or dissimilar to outer control layers; and other physicalmethods, such as osmotic pumps, or adsorption onto ion-exchange resins.

Chemical systems include, but are not limited to, chemical erosion ofpolymer matrices (e.g., heterogeneous, or homogeneous erosion), orbiological erosion of a polymer matrix (e.g., heterogeneous, orhomogeneous). Additional discussion of categories of systems forcontrolled release can be found in Agis F. Kydonieus, Controlled ReleaseTechnologies: Methods, Theory and Applications, 1980 (CRC Press, Inc.).

There are a number of controlled release drug formulations that aredeveloped for oral administration. These include, but are not limitedto, osmotic pressure-controlled gastrointestinal delivery systems;hydrodynamic pressure-controlled gastrointestinal delivery systems;membrane permeation-controlled gastrointestinal delivery systems, whichinclude microporous membrane permeation-controlled gastrointestinaldelivery devices; gastric fluid-resistant intestine targetedcontrolled-release gastrointestinal delivery devices; geldiffusion-controlled gastrointestinal delivery systems; andion-exchange-controlled gastrointestinal delivery systems, which includecationic and anionic drugs. Additional information regarding controlledrelease drug delivery systems can be found in Yie W. Chien, Novel DrugDelivery Systems, 1992 (Marcel Dekker, Inc.).

Dosages

A suitable dosage can be determined by an attending physician or otherqualified medical personnel, based on various clinical factors. As iswell known in the medical arts, dosages for any one patient depend uponmany factors, including the patient's size, body surface area, age, theparticular compound to be administered, sex of the patient, time, androute of administration, general health, and other drugs beingadministered concurrently. A subject antibody can be administered inamounts between 1 ng/kg body weight and 20 mg/kg body weight per dose,e.g. between 0.1 mg/kg body weight to 10 mg/kg body weight, e.g. between0.5 mg/kg body weight to 5 mg/kg body weight; however, doses below orabove this exemplary range are envisioned, especially considering theaforementioned factors. If the regimen is a continuous infusion, it canalso be in the range of 1 μg to 10 mg per kilogram of body weight perminute.

In some embodiments, a dose of a subject anti-C1s antibody is in therange of 0.001 μg to 1000 μg; however, doses below or above thisexemplary range are envisioned, especially considering theaforementioned factors. In some embodiments, the dosage can range, e.g.,from about 0.0001 to 100 mg/kg, or from about 0.01 to 5 mg/kg (e.g.,0.02 mg/kg, 0.25 mg/kg, 0.5 mg/kg, 0.75 mg/kg, 1 mg/kg, 2 mg/kg, etc.)body weight. For example dosages can be 1 mg/kg body weight or 10 mg/kgbody weight or within the range of 1-10 mg/kg, or at least 1 mg/kg.Doses intermediate in the above ranges are also intended to be withinthe scope of the invention.

In some embodiments, a subject anti-C1s antibody is administered in anamount that provides for a peak serum concentration of from about 1μg/ml to about 1 mg/ml, e.g., from about 1 μg/ml to about 2.5 μg/ml,from about 2.5 μg/ml to about 5 μg/ml, from about 5 μg/ml to about 7.5μg/ml, from about 7.5 μg/ml to about 10 μg/ml, from about 10 μg/ml toabout 25 μg/ml, from about 25 μg/ml to about 50 μg/ml, from about 50μg/ml to about 100 μg/ml, from about 100 μg/ml to about 250 μg/ml, fromabout 250 μg/ml to about 500 μg/ml, from about 500 μg/ml to about 750μg/ml, or from about 750 μg/ml to about 1000 μg/ml. In some embodiments,a subject anti-C1s antibody is administered in an amount that providesfor a peak serum concentration of greater than 1 mg/ml, e.g., from about1 mg/ml to about 2 mg/ml, from about 2 mg/ml to about 5 mg/ml, or fromabout 5 mg/ml to about 10 mg/ml.

Individuals can be administered such doses daily, on alternative days,weekly or according to any other schedule determined by empiricalanalysis. An exemplary treatment entails administration in multipledosages over a prolonged period, for example, of at least six months.Additional exemplary treatment regimens entail administration once perevery two weeks or once a month or once every 3 to 6 months. Exemplarydosage schedules include 1-10 mg/kg or 15 mg/kg on consecutive days, 30mg/kg on alternate days or 60 mg/kg weekly. In some methods, two or moremonoclonal antibodies with different binding specificities areadministered simultaneously, in which case the dosage of each antibodyadministered falls within the ranges indicated. Progress can bemonitored by periodic assessment.

Those of skill will readily appreciate that dose levels andadministration schedules can vary as a function of the specificantibody, the severity of the symptoms and the susceptibility of thesubject to side effects. Preferred dosages and administration schedulesfor a given compound are readily determinable by those of skill in theart by a variety of means.

Routes of Administration

A subject antibody is administered to an individual using any availablemethod and route suitable for drug delivery, including in vivo and exvivo methods, as well as systemic and localized routes ofadministration.

Conventional and pharmaceutically acceptable routes of administrationinclude intranasal, intramuscular, intratracheal, intrathecal,intracranial, subcutaneous, intradermal, topical, intravenous,intraperitoneal, intraarterial (e.g., via the carotid artery), spinal orbrain delivery, rectal, nasal, oral, and other enteral and parenteralroutes of administration. Routes of administration can be combined, ifdesired, or adjusted depending upon the antibody and/or the desiredeffect. A subject antibody composition can be administered in a singledose or in multiple doses. In some embodiments, a subject antibodycomposition is administered orally. In some embodiments, a subjectantibody composition is administered via an inhalational route. In someembodiments, a subject antibody composition is administeredintranasally. In some embodiments, a subject antibody composition isadministered locally. In some embodiments, a subject antibodycomposition is administered intracranially. In some embodiments, asubject antibody composition is administered intravenously. In someembodiments, a subject antibody composition is administeredintrathecally.

An antibody of the present disclosure can be administered to a hostusing any available conventional methods and routes suitable fordelivery of conventional drugs, including systemic or localized routes.In general, routes of administration contemplated by the inventioninclude, but are not necessarily limited to, enteral, parenteral, orinhalational routes.

Parenteral routes of administration other than inhalation administrationinclude, but are not necessarily limited to, topical, transdermal,subcutaneous, intramuscular, intraorbital, intracapsular, intraspinal,intrasternal, intrathecal, and intravenous routes, i.e., any route ofadministration other than through the alimentary canal. Parenteraladministration can be carried to effect systemic or local delivery of asubject antibody. Where systemic delivery is desired, administrationtypically involves invasive or systemically absorbed topical or mucosaladministration of pharmaceutical preparations.

A subject antibody can also be delivered to the subject by enteraladministration. Enteral routes of administration include, but are notnecessarily limited to, oral and rectal (e.g., using a suppository)delivery.

By treatment is meant at least an amelioration of the symptomsassociated with the pathological condition afflicting the host, whereamelioration is used in a broad sense to refer to at least a reductionin the magnitude of a parameter, e.g. symptom, associated with thepathological condition being treated, such as a complement-mediateddisease or disorder. As such, treatment also includes situations wherethe pathological condition, or at least symptoms associated therewith,are completely inhibited, e.g. prevented from happening, or stopped,e.g. terminated, such that the host no longer suffers from thepathological condition, or at least the symptoms that characterize thepathological condition.

In some embodiments, a subject antibody is administered by injectionand/or delivery, e.g., to a site in a brain artery or directly intobrain tissue. A subject antibody can also be administered directly to atarget site e.g., by biolistic delivery to the target site.

A variety of hosts (wherein the term “host” is used interchangeablyherein with the terms “subject,” “individual,” and “patient”) aretreatable according to the subject methods. Generally such hosts are“mammals” or “mammalian,” where these terms are used broadly to describeorganisms which are within the class mammalia, including the orderscarnivore (e.g., cats), herbivores (e.g., cattle, horses, and sheep),omnivores (e.g., dogs, goats, and pigs), rodentia (e.g., mice, guineapigs, and rats), and primates (e.g., humans, chimpanzees, and monkeys).In some embodiments, the host is an individual that has a complementsystem, such as a mammal, fish, or invertebrate. In some embodiments,the host is a complement system-containing mammal, fish, or invertebratecompanion animal, agricultural animal, work animal, zoo animal, or labanimal. In some embodiments, the host is human.

The embodiments include compositions comprising a container suitable forcontaining a composition comprising a subject anti-C1s antibody foradministration to an individual. For example, a subject antibody can bedisposed within a container suitable for containing a pharmaceuticalcomposition. The container can be, for example, a bottle (e.g., with aclosure device, such as a cap), a blister pack (e.g., which can providefor enclosure of one or more doses per blister), a vial, flexiblepackaging (e.g., sealed Mylar or plastic bags), an ampule (for singledoses in solution), a dropper, a syringe, thin film, a tube and thelike. In some embodiments, a container, such as a sterile container,comprises a subject pharmaceutical composition. In some embodiments thecontainer is a bottle or a syringe. In some embodiments the container isa bottle. In some embodiments the container is a syringe.

Kits with unit doses of a subject antibody, e.g. in oral or injectabledoses, are provided. In such kits, in addition to the containerscontaining the unit doses will be an informational package insertdescribing the use and attendant benefits of the antibody in treatingpathological condition of interest. Preferred compounds and unit dosesare those described herein above.

Methods of Treating a Complement-Mediated Disease or Disorder

The present disclosure provides methods of treating acomplement-mediated disease or disorder. The methods generally involveadministering an effective amount of an anti-C1s antibody of the presentdisclosure, or a pharmaceutical composition comprising such an antibody,to an individual in need thereof. In some cases, administration of asubject anti-C1s antibody modulates the activity of complement C1s in acell, a tissue, or a fluid of an individual, and treats thecomplement-mediated disease or disorder. The present disclosure providesmethods of inhibiting activation of complement component C4 in anindividual, the methods comprising administering to the individual aneffective amount of an anti-C1s antibody of the present disclosure or apharmaceutical composition comprising such an antibody. The presentdisclosure provides methods of inhibiting complement C1s activity in anindividual the methods comprising administering to the individual aneffective amount of an anti-C1s antibody of the present disclosure or apharmaceutical composition comprising such an antibody.

In some embodiments, a method of the present disclosure to treat anindividual having a complement-mediated disease or disorder comprisesadministering to the individual an effective amount of an anti-C1santibody of the present disclosure or an effective amount of apharmaceutical composition comprising: a) an anti-C1s antibody of thepresent disclosure; and a pharmaceutically acceptable excipient suitablefor administration to such individual. In some embodiments, theindividual is a mammal. In some embodiments, the individual is a human.Administering can be by any route known to those skilled in the art,including those disclosed herein. In some embodiments, administering isintravenous. In some embodiments, administering is intrathecal. In someembodiments, administering is subcutaneous.

In some embodiments, an “effective amount” of an anti-C1s antibody ofthe present disclosure, or an “effective amount” of a subjectpharmaceutical composition comprising an anti-C1s antibody of thepresent disclosure, is an amount that, when administered in one or moredoses to an individual in need thereof, reduces production of C4b2a(i.e., complement C4b and C2a complex; also known as “C3 convertase”) inthe individual (or in a tissue or organ of the individual) by at least10%, at least 20%, at least 30%, at least 40%, at least 50%, at least60%, at least 65%, at least 70%, at least 75%, at least 80%, at least85%, at least 90%, at least 95%, or 100%, compared to the amount ofC4b2a produced in the individual, or the tissue or organ, in the absenceof a subject anti-C1s antibody. In some embodiments, the individual is amammal. In some embodiments, the individual is a human. Administeringcan be by any route known to those skilled in the art, including thosedisclosed herein. In some embodiments, administering is intravenous. Insome embodiments, the route of administration is intrathecal. In someembodiments, the route of administration is intravenous. In someembodiments, the route of administration is subcutaneous.

The present disclosure provides a method to modulate complementactivation. In some embodiments the method inhibits complementactivation, for example to reduce production of C4b2a. In someembodiments, the present disclosure provides a method to modulatecomplement activation in an individual having a complement-mediateddisease or disorder, the method comprising administering to theindividual an anti-C1s antibody of the present disclosure or apharmaceutical composition of the present disclosure, wherein thepharmaceutical composition comprises an anti-C1s antibody of the presentdisclosure. In some embodiments such a method inhibits complementactivation. In some embodiments, the individual is a mammal. In someembodiments, the individual is a human. Administering can be by anyroute known to those skilled in the art, including those disclosedherein. In some embodiments, administering is intravenous. In someembodiments, administering is intrathecal.

A complement-mediated disease or disorder is a disorder characterized byan abnormal amount of complement C1s or an abnormal level of complementC1s proteolytic activity in a cell, a tissue, or a fluid of anindividual.

In some cases, a complement-mediated disease or disorder ischaracterized by the presence in a cell, a tissue, or a fluid of anelevated (higher than normal) amount of C1s or of an elevated level ofcomplement C1s activity. For example, in some cases, acomplement-mediated disease or disorder is characterized by the presencein brain tissue and/or cerebrospinal fluid of an elevated amount and/oran elevated activity of C1s. A “higher than normal” amount of C1s in acell, a tissue, or a fluid indicates that the amount of C1s in the cell,tissue or fluid is higher than a normal, control level, e.g., higherthan a normal, control level for an individual or population ofindividuals of the same age group. A “higher than normal” level of C1sactivity in a cell, a tissue, or a fluid indicates that the proteolyticcleavage effected by C1s in the cell, tissue or fluid is higher than anormal, control level, e.g., higher than a normal, control level for anindividual or population of individuals of the same age group. In somecases, an individual having a complement-mediated disease or disorderexhibits one or more additional symptoms of such a disease or disorder.

In other cases, a complement-mediated disease or disorder ischaracterized by the presence in a cell, a tissue, or a fluid of a lowerthan normal amount of C1s or of a lower level of complement C1sactivity. For example, in some cases, a complement-mediated disease ordisorder is characterized by the presence in brain tissue and/orcerebrospinal fluid of a lower amount and/or a lower activity of C1s. A“lower than normal” amount of C1s in a cell, a tissue, or a fluidindicates that the amount of C1s in the cell, tissue or fluid is lowerthan a normal, control level, e.g., lower than a normal, control levelfor an individual or population of individuals of the same age group. A“lower than normal” level of C1s activity in a cell, a tissue, or afluid indicates that the proteolytic cleavage effected by C1s in thecell, tissue or fluid is lower than a normal, control level, e.g., lowerthan a normal, control level for an individual or population ofindividuals of the same age group. In some cases, an individual having acomplement-mediated disease or disorder exhibits one or more additionalsymptoms of such a disease or disorder.

A complement-mediated disease or disorder is a disease or disorder inwhich the amount or activity of complement C1s is such as to causedisease or disorder in an individual. In some embodiments, thecomplement-mediated disease or disorder is selected from the groupconsisting of autoimmune disease, cancer, hematological disease,infectious disease, inflammatory disease, ischemia-reperfusion injury,neurodegenerative disease, neurodegenerative disorder, ocular disease,renal disease, transplant rejection, vascular disease, and vasculitisdisease. In some embodiments, the complement-mediated disease ordisorder is an autoimmune disease. In some embodiments, thecomplement-mediated disease or disorder is cancer. In some embodiments,the complement-mediated disease or disorder is an infectious disease. Insome embodiments, the complement-mediated disease or disorder is aninflammatory disease. In some embodiments, the complement-mediateddisease or disorder is a hematological disease. In some embodiments, thecomplement-mediated disease or disorder is an ischemia-reperfusioninjury. In some embodiments, the complement-mediated disease or disorderis ocular disease. In some embodiments, the complement-mediated diseaseor disorder is a renal disease. In some embodiments, thecomplement-mediated disease or disorder is transplant rejection. In someembodiments, the complement-mediated disease or disorder isantibody-mediated transplant rejection. In some embodiments, thecomplement-mediated disease or disorder is a vascular disease. In someembodiments, the complement-mediated disease or disorder is a vasculitisdisorder. In some embodiments, the complement-mediated disease ordisorder is a neurodegenerative disease or disorder. In someembodiments, the complement-mediated disease is a neurodegenerativedisease. In some embodiments, the complement-mediated disorder is aneurodegenerative disorder. In some embodiments, the complement-mediateddisease or disorder is a tauopathy.

Examples of a complement-mediated disease or disorder include, but arenot limited to, age-related macular degeneration, Alzheimer's disease,amyotrophic lateral sclerosis, anaphylaxis, argyrophilic grain dementia,arthritis (e.g., rheumatoid arthritis), asthma, atherosclerosis,atypical hemolytic uremic syndrome, autoimmune diseases,Barraquer-Simons syndrome, Behcet's disease, British type amyloidangiopathy, bullous pemphigoid, Buerger's disease, C1q nephropathy,cancer, catastrophic antiphospholipid syndrome, cerebral amyloidangiopathy, cold agglutinin disease, corticobasal degeneration,Creutzfeldt-Jakob disease, Crohn's disease, cryoglobulinemic vasculitis,dementia pugilistica, dementia with Lewy Bodies (DLB), diffuseneurofibrillary tangles with calcification, Discoid lupus erythematosus,Down's syndrome, focal segmental glomerulosclerosis, formal thoughtdisorder, frontotemporal dementia (FTD), frontotemporal dementia withparkinsonism linked to chromosome 17, frontotemporal lobar degeneration,Gerstmann-Straussler-Scheinker disease, Guillain-Barre syndrome,Hallervorden-Spatz disease, hemolytic-uremic syndrome, hereditaryangioedema, hypophosphastasis, idiopathic pneumonia syndrome, immunecomplex diseases, inclusion body myositis, infectious disease (e.g.,disease caused by bacterial (e.g., Neisseria meningitidis orStreptococcus) viral (e.g., human immunodeficiency virus (HIV)), orother infectious agents), inflammatory disease, ischemia/reperfusioninjury, mild cognitive impairment, immunothrombocytopenic purpura (ITP),molybdenum cofactor deficiency (MoCD) type A, membranoproliferativeglomerulonephritis (MPGN) I, membranoproliferative glomerulonephritis(MPGN) II (dense deposit disease), membranous nephritis, multi-infarctdementia, lupus (e.g., systemic lupus erythematosus (SLE)),glomerulonephritis, Kawasaki disease, multifocal motor neuropathy,multiple sclerosis, multiple system atrophy, myasthenia gravis,myocardial infarction, myotonic dystrophy, neuromyelitis optica,Niemann-Pick disease type C, non-Guamanian motor neuron disease withneurofibrillary tangles, Parkinson's disease, Parkinson's disease withdementia, paroxysmal nocturnal hemoglobinuria, Pemphigus vulgaris,Pick's disease, postencephalitic parkinsonism, polymyositis, prionprotein cerebral amyloid angiopathy, progressive subcortical gliosis,progressive supranuclear palsy, psoriasis, sepsis, Shiga-toxin E. coli(STEC)-HuS, spinal muscular atrophy, stroke, subacute sclerosingpanencephalitis, Tangle only dementia, transplant rejection, vasculitis(e.g., ANCA associated vasculitis), Wegner's granulomatosis, sickle celldisease, cryoglobulinemia, mixed cryoglobulinemia, essential mixedcryoglobulinemia, Type II mixed cryoglobulinemia, Type III mixedcryoglobulinemia, nephritis, drug-induced thrombocytopenia, lupusnephritis, bullous pemphigoid, Epidermolysis bullosa acquisita, delayedhemolytic transfusion reaction, hypocomplementemic urticarial vasculitissyndrome, pseudophakic bullous keratopathy, and platelet refractoriness.

Alzheimer's disease and certain forms of Frontotemporal dementia (Pick'sdisease, sporadic Frontotemporal dementia and Frontotemporal dementiawith Parkinsonism linked to chromosome 17) are the most common forms oftauopathy. In accordance, the present invention relates to any method asdescribed above, wherein the tauopathy is Alzheimer's, Pick's disease,sporadic Frontotemporal dementia and Frontotemporal dementia withParkinsonism linked to chromosome 17. Other tauopathies include but arenot limited to Progressive supranuclear palsy (PSP), Corticobasaldegeneration (CBD) and Subacute sclerosing panencephalitis.

A neurodegenerative tauopathy includes Alzheimer's disease, amyotrophiclateral sclerosis/parkinsonism-dementia complex, argyrophilic graindementia, British type amyloid angiopathy, cerebral amyloid angiopathy,corticobasal degeneration, Creutzfeldt-Jakob disease, dementiapugilistica, diffuse neurofibrillary tangles with calcification, Down'ssyndrome, frontotemporal dementia, frontotemporal dementia withparkinsonism linked to chromosome 17, frontotemporal lobar degeneration,Gerstmann-Straussler-Scheinker disease, Hallervorden-Spatz disease,inclusion body myositis, multiple system atrophy, myotonic dystrophy,Niemann-Pick disease type C, non-Guamanian motor neuron disease withneurofibrillary tangles, Pick's disease, postencephalitic parkinsonism,prion protein cerebral amyloid angiopathy, progressive subcorticalgliosis, progressive supranuclear palsy, subacute sclerosingpanencephalitis, Tangle only dementia, multi-infarct dementia, ischemicstroke, chronic traumatic encephalopathy (CTE), traumatic brain injury(TBI), and stroke.

The present disclosure also provides methods of treating asynucleinopathy, e.g., Parkinson's disease (PD); dementia with LewyBodies (DLB); multiple system atrophy (MSA); etc. For example, PD withdementia (PDD) can be treated with a subject method.

In some embodiments, the complement-mediated disease or disordercomprises Alzheimer's disease. In some embodiments, thecomplement-mediated disease or disorder comprises Parkinson's disease.In some embodiments, the complement-mediated disease or disordercomprises transplant rejection. In some embodiments, thecomplement-mediated disease or disorder is antibody-mediated transplantrejection.

In some embodiments, an anti-C1s antibody of the present disclosureprevents or delays the onset of at least one symptom of acomplement-mediated disease or disorder in an individual. In someembodiment, an anti-C1s antibody of the present disclosure reduces oreliminates at least one symptom of a complement-mediated disease ordisorder in an individual. Examples of symptoms include, but are notlimited to, symptoms associated with autoimmune disease, cancer,hematological disease, infectious disease, inflammatory disease,ischemia-reperfusion injury, neurodegenerative disease,neurodegenerative disorder, renal disease, transplant rejection, oculardisease, vascular disease, or a vasculitis disorder. The symptom can bea neurological symptom, for example, impaired cognitive function, memoryimpairment, loss of motor function, etc. The symptom can also be theactivity of C1s protein in a cell, tissue, or fluid of an individual.The symptom can also be the extent of complement activation in a cell,tissue, or fluid of an individual.

In some embodiments, administering an anti-C1s antibody of the presentdisclosure to an individual modulates complement activation in a cell,tissue, or fluid of an individual. In some embodiments, administrationof a subject anti-C1s antibody to an individual inhibits complementactivation in a cell, tissue, or fluid of an individual. For example, insome embodiments, a subject anti-C1s antibody, when administered in oneor more doses as monotherapy or in combination therapy to an individualhaving a complement-mediated disease or disorder, inhibits complementactivation in the individual by at least about 10%, at least about 15%,at least about 20%, at least about 25%, at least about 30%, at leastabout 40%, at least about 50%, at least about 60%, at least about 70%,at least about 80%, at least about 90%, or more than 90%, compared tocomplement activation in the individual before treatment with theanti-C1s antibody.

In some embodiments, an anti-C1s antibody of the present disclosurereduces C3 deposition onto red blood cells; for example, in someembodiments, an anti-C1s antibody of the present disclosure reducesdeposition of C3b, iC3b, etc., onto RBCs). In some embodiments, ananti-C1s antibody of the present disclosure inhibits complement-mediatedred blood cell lysis.

In some embodiments, an anti-C1s antibody of the present disclosurereduces C3 deposition onto platelets; for example, in some embodiments,an anti-C1s antibody of the present disclosure reduces deposition ofC3b, iC3b, etc., onto platelets).

In some embodiments, administering an anti-C1s antibody of the presentdisclosure results in an outcome selected from the group consisting of:(a) a reduction in complement activation; (b) an improvement incognitive function; (c) a reduction in neuron loss; (d) a reduction inphospho-Tau levels in neurons; (e) a reduction in glial cell activation;(f) a reduction in lymphocyte infiltration; (g) a reduction inmacrophage infiltration; (h) a reduction in antibody deposition, (i) areduction in glial cell loss; (j) a reduction in oligodendrocyte loss;(k) a reduction in dendritic cell infiltration; (1) a reduction inneutrophil infiltration; (m) a reduction in red blood cell lysis; (n) areduction in red blood cell phagocytosis; (o) a reduction in plateletphagocytosis; (p) a reduction in platelet lysis; (q) an improvement intransplant graft survival; (r) a reduction in macrophage mediatedphagocytosis; (s) an improvement in vision; (t) an improvement in motorcontrol; (u) an improvement in thrombus formation; (v) an improvement inclotting; (w) an improvement in kidney function; (x) a reduction inantibody mediated complement activation; (y) a reduction in autoantibodymediated complement activation; (z) an improvement in anemia; (aa)reduction of demyelination; (ab) reduction of eosinophilia; (ac) areduction of C3 deposition on red blood cells (e.g., a reduction ofdeposition of C3b, iC3b, etc., onto RBCs); and (ad) a reduction in C3deposition on platelets (e.g., a reduction of deposition of C3b, iC3b,etc., onto platelets); and (ae) a reduction of anaphylatoxin toxinproduction; (af) a reduction in autoantibody mediated blister formation;(ag) a reduction in autoantibody induced pruritis; (ah) a reduction inautoantibody induced erythematosus; (ai) a reduction in autoantibodymediated skin erosion; (aj) a reduction in red blood cell destructiondue to transfusion reactions; (ak) a reduction in red blood cell lysisdue to alloantibodies; (al) a reduction in hemolysis due to transfusionreactions; (am) a reduction in allo-antibody mediated platelet lysis;(an) a reduction in platelet lysis due to transfusion reactions; (ao) areduction in mast cell activation; (ap) a reduction in mast cellhistamine release; (aq) a reduction in vascular permeability; (ar) areduction in edema; (as) a reduction in complement deposition ontransplant graft endothelium; (at) a reduction of anaphylatoxingeneration in transplant graft endothelium; (au) a reduction in theseparation of the dermal-epidermal junction; (av) a reduction in thegeneration of anaphylatoxins in the dermal-epidermal junction; (aw) areduction in alloantibody mediated complement activation in transplantgraft endothelium; (ax) a reduction in antibody mediated loss of theneuromuscular junction; (ay) a reduction in complement activation at theneuromuscular junction; (az) a reduction in anaphylatoxin generation atthe neuromuscular junction; (ba) a reduction in complement deposition atthe neuromuscular junction; (bb) a reduction in paralysis; (bc) areduction in numbness; (bd) increased bladder control; (be) increasedbowel control; (bf) a reduction in mortality associated withautoantibodies; and (bg) a reduction in morbidity associated withautoantibodies.

In some embodiments, a subject anti-C1s antibody, when administered inone or more doses as monotherapy or in combination therapy to anindividual having a complement-mediated disease or disorder, is effectto achieve a reduction of at least about 10%, at least about 15%, atleast about 20%, at least about 25%, at least about 30%, at least about40%, at least about 50%, at least about 60%, at least about 70%, atleast about 80%, at least about 90%, or more than 90%, of one or more ofthe following outcomes: (a) complement activation; (b) decline incognitive function; (c) neuron loss; (d) phospho-Tau levels in neurons;(e) glial cell activation; (f) lymphocyte infiltration; (g) macrophageinfiltration; (h) antibody deposition, (i) glial cell loss; (j)oligodendrocyte loss; (k) dendritic cell infiltration; (1) neutrophilinfiltration; (m) red blood cell lysis; (n) red blood cell phagocytosis;(O) platelet phagocytosis; (p) platelet lysis; (q) transplant graftrejection; (r) macrophage mediated phagocytosis; (s) vision loss; (t)antibody mediated complement activation; (u) autoantibody mediatedcomplement activation; (v) demyelination; (w) eosinophilia; compared tothe level or degree of the outcome in the individual before treatmentwith the anti-C1s antibody.

In some embodiments, a subject anti-C1s antibody, when administered inone or more doses as monotherapy or in combination therapy to anindividual having a complement-mediated disease or disorder, is effectto achieve an improvement of at least about 10%, at least about 15%, atleast about 20%, at least about 25%, at least about 30%, at least about40%, at least about 50%, at least about 60%, at least about 70%, atleast about 80%, at least about 90%, or more than 90%, of one or more ofthe following outcomes: a) cognitive function; b) transplant graftsurvival; c) vision; d) motor control; e) thrombus formation; f)clotting; g) kidney function; and h) hematocrit (red blood cell count),compared to the level or degree of the outcome in the individual beforetreatment with the anti-C1s antibody.

In some embodiments, administering an anti-C1s antibody of the presentdisclosure to an individual reduces complement activation in theindividual. For example, in some embodiments, a subject anti-C1santibody, when administered in one or more doses as monotherapy or incombination therapy to an individual having a complement-mediateddisease or disorder, reduces complement activation in the individual byat least about 10%, at least about 15%, at least about 20%, at leastabout 25%, at least about 30%, at least about 40%, at least about 50%,at least about 60%, at least about 70%, at least about 80%, at leastabout 90%, or more than 90%, compared to complement activation in theindividual before treatment with the anti-C1s antibody.

In some embodiments, administering an anti-C1s antibody of the presentdisclosure improves cognitive function in the individual. For example,in some embodiments, a subject anti-C1s antibody, when administered inone or more doses as monotherapy or in combination therapy to anindividual having a complement-mediated disease or disorder, improvescognitive function in the individual by at least about 10%, at leastabout 15%, at least about 20%, at least about 25%, at least about 30%,at least about 40%, at least about 50%, at least about 60%, at leastabout 70%, at least about 80%, at least about 90%, or more than 90%,compared to the cognitive function in the individual before treatmentwith the anti-C1s antibody.

In some embodiments, administering an anti-C1s antibody of the presentdisclosure reduces the rate of decline in cognitive function in theindividual. For example, in some embodiments, a subject anti-C1santibody, when administered in one or more doses as monotherapy or incombination therapy to an individual having a complement-mediateddisease or disorder, reduces the rate of decline of cognitive functionin the individual by at least about 10%, at least about 15%, at leastabout 20%, at least about 25%, at least about 30%, at least about 40%,at least about 50%, at least about 60%, at least about 70%, at leastabout 80%, at least about 90%, or more than 90%, compared to the rate ofdecline in cognitive function in the individual before treatment withthe anti-C1s antibody.

In some embodiments, administering an anti-C1s antibody of the presentdisclosure to an individual reduces neuron loss in the individual. Forexample, in some embodiments, a subject anti-C1s antibody, whenadministered in one or more doses as monotherapy or in combinationtherapy to an individual having a complement-mediated disease ordisorder, reduces neuron loss in the individual by at least about 10%,at least about 15%, at least about 20%, at least about 25%, at leastabout 30%, at least about 40%, at least about 50%, at least about 60%,at least about 70%, at least about 80%, at least about 90%, or more than90%, compared to neuron loss in the individual before treatment with theanti-C1s antibody.

In some embodiments, administering an anti-C1s antibody of the presentdisclosure to an individual reduces phospho-Tau levels in theindividual. For example, in some embodiments, a subject anti-C1santibody, when administered in one or more doses as monotherapy or incombination therapy to an individual having a complement-mediateddisease or disorder, reduces phospho-Tau in the individual by at leastabout 10%, at least about 15%, at least about 20%, at least about 25%,at least about 30%, at least about 40%, at least about 50%, at leastabout 60%, at least about 70%, at least about 80%, at least about 90%,or more than 90%, compared to the phospho-Tau level in the individualbefore treatment with the anti-C1s antibody.

In some embodiments, administering an anti-C1s antibody of the presentdisclosure to an individual reduces glial cell activation in theindividual. For example, in some embodiments, a subject anti-C1santibody, when administered in one or more doses as monotherapy or incombination therapy to an individual having a complement-mediateddisease or disorder, reduces glial activation in the individual by atleast about 10%, at least about 15%, at least about 20%, at least about25%, at least about 30%, at least about 40%, at least about 50%, atleast about 60%, at least about 70%, at least about 80%, at least about90%, or more than 90%, compared to glial cell activation in theindividual before treatment with the anti-C1s antibody. In someembodiments, the glial cells are astrocytes or microglia.

In some embodiments, administering an anti-C1s antibody of the presentdisclosure to an individual reduces lymphocyte infiltration in theindividual. For example, in some embodiments, a subject anti-C1santibody, when administered in one or more doses as monotherapy or incombination therapy to an individual having a complement-mediateddisease or disorder, reduces lymphocyte infiltration in the individualby at least about 10%, at least about 15%, at least about 20%, at leastabout 25%, at least about 30%, at least about 40%, at least about 50%,at least about 60%, at least about 70%, at least about 80%, at leastabout 90%, or more than 90%, compared to lymphocyte infiltration in theindividual before treatment with the anti-C1s antibody.

In some embodiments, administering an anti-C1s antibody of the presentdisclosure to an individual reduces macrophage infiltration in theindividual. For example, in some embodiments, a subject anti-C1santibody, when administered in one or more doses as monotherapy or incombination therapy to an individual having a complement-mediateddisease or disorder, reduces macrophage infiltration in the individualby at least about 10%, at least about 15%, at least about 20%, at leastabout 25%, at least about 30%, at least about 40%, at least about 50%,at least about 60%, at least about 70%, at least about 80%, at leastabout 90%, or more than 90%, compared to macrophage infiltration in theindividual before treatment with the anti-C1s antibody.

In some embodiments, administering an anti-C1s antibody of the presentdisclosure to an individual reduces antibody deposition in theindividual. For example, in some embodiments, a subject anti-C1santibody, when administered in one or more doses as monotherapy or incombination therapy to an individual having a complement-mediateddisease or disorder, reduces antibody deposition in the individual by atleast about 10%, at least about 15%, at least about 20%, at least about25%, at least about 30%, at least about 40%, at least about 50%, atleast about 60%, at least about 70%, at least about 80%, at least about90%, or more than 90%, compared to antibody deposition in the individualbefore treatment with the anti-C1s antibody.

In some embodiments, administering an anti-C1s antibody of the presentdisclosure to an individual reduces anaphylatoxin (e.g., C3a, C4a, C5a)production in an individual. For example, in some embodiments, a subjectanti-C1s antibody, when administered in one or more doses as monotherapyor in combination therapy to an individual having a complement-mediateddisease or disorder, reduces anaphylatoxin production in the individualby at least about 10%, at least about 15%, at least about 20%, at leastabout 25%, at least about 30%, at least about 40%, at least about 50%,at least about 60%, at least about 70%, at least about 80%, at leastabout 90%, or more than 90%, compared to the level of anaphylatoxinproduction in the individual before treatment with the anti-C1santibody.

The present disclosure provides for use of an anti-C1s antibody of thepresent disclosure or a pharmaceutical composition comprising ananti-C1s antibody of the present disclosure and a pharmaceuticallyacceptable excipient to treat an individual having a complement-mediateddisease or disorder. In some embodiments, the present disclosureprovides for use of an anti-C1s antibody of the present disclosure totreat an individual having a complement-mediated disease or disorder. Insome embodiments, the present disclosure provides for use of apharmaceutical composition comprising an anti-C1s antibody of thepresent disclosure and a pharmaceutically acceptable excipient to treatan individual having a complement-mediated disease or disorder.

The present disclosure provides for use of an anti-C1s antibody of thepresent disclosure in the manufacture of a medicament for the treatmentof an individual having a complement-mediated disease or disorder.

The present disclosure provides for use of an anti-C1s antibody of thepresent disclosure or a pharmaceutical composition comprising ananti-C1s antibody of the present disclosure and a pharmaceuticallyacceptable excipient to inhibit complement activation. In someembodiments, the present disclosure provides for use of an anti-C1santibody of the present disclosure or a pharmaceutical compositioncomprising an anti-C1s antibody of the present disclosure and apharmaceutically acceptable excipient to inhibit complement activationin an individual having a complement-mediated disease or disorder. Insome embodiments, the present disclosure provides for use of an anti-C1santibody of the present disclosure to inhibit complement activation inan individual having a complement-mediated disease or disorder. In someembodiments, the present disclosure provides for use of a pharmaceuticalcomposition comprising an anti-C1s antibody of the present disclosureand a pharmaceutically acceptable excipient to inhibit complementactivation in an individual having a complement-mediated disease ordisorder.

The present disclosure provides for use of an anti-C1s antibody of thepresent disclosure in the manufacture of a medicament for modulatingcomplement activation. In some embodiments, the medicament inhibitscomplement activation. In some embodiments, the medicament inhibitscomplement activation in an individual having a complement-mediateddisease or disorder.

The present disclosure provides for an anti-C1s antibody of the presentdisclosure or a pharmaceutical composition comprising an anti-C1santibody of the present disclosure and a pharmaceutically acceptableexcipient for use in medical therapy. In some embodiments, the presentdisclosure provides for an anti-C1s antibody of the present disclosurefor use in medical therapy. In some embodiments, the present disclosureprovides for a pharmaceutical composition comprising an anti-C1santibody of the present disclosure and a pharmaceutically acceptableexcipient for use in medical therapy.

The present disclosure provides for an anti-C1s antibody of the presentdisclosure or a pharmaceutical composition comprising an anti-C1santibody of the present disclosure and a pharmaceutically acceptableexcipient for treating an individual having a complement-mediateddisease or disorder. In some embodiments, the present disclosureprovides for an anti-C1s antibody of the present disclosure for treatingan individual having a complement-mediated disease or disorder. In someembodiments, the present disclosure provides for a pharmaceuticalcomposition comprising an anti-C1s antibody of the present disclosureand a pharmaceutically acceptable excipient for treating an individualhaving a complement-mediated disease or disorder.

The present disclosure provides for an anti-C1s antibody of the presentdisclosure or a pharmaceutical composition comprising an anti-C1santibody of the present disclosure and a pharmaceutically acceptableexcipient for modulating complement activation. In some embodiments, thepresent disclosure provides for an anti-C1s antibody of the presentdisclosure for modulating complement activation. In some embodiments,the present disclosure provides for a pharmaceutical compositioncomprising an anti-C1s antibody of the present disclosure and apharmaceutically acceptable excipient for modulating complementactivation. In some embodiments, the anti-C1s antibody inhibitscomplement activation.

Combination Therapy

An anti-C1s antibody of the present disclosure can be administered to anindividual in need thereof alone (e.g., as monotherapy); or incombination therapy with one or more additional therapeutic agents.

For the treatment of AD, suitable additional therapeutic agents include,but are not limited to, acetylcholinesterase inhibitors, including, butnot limited to, Aricept (donepezil), Exelon (rivastigmine), metrifonate,and tacrine (Cognex); an anti-Aβ antibody; non-steroidalanti-inflammatory agents, including, but not limited to, ibuprofen andindomethacin; cyclooxygenase-2 (Cox2) inhibitors such as Celebrex; andmonoamine oxidase inhibitors, such as Selegilene (Eldepryl or Deprenyl).Dosages for each of the above agents are known in the art.

Another suitable additional therapeutic agent in the treatment of AD isan agent that inhibits tau aggregation, e.g., a napthoquinone derivativethat inhibits tau aggregation, as described in U.S. Pat. No. 7,605,179.Another suitable additional therapeutic agent is an agent that inhibitsphosphorylation of tau, e.g., a 3-substituted-4-pyrimidone derivativethat inhibits tau protein kinase 1, as described in U.S. Pat. No.7,572,793.

“In combination with” as used herein refers to uses where, for example,the first compound is administered during the entire course ofadministration of the second compound; where the first compound isadministered for a period of time that is overlapping with theadministration of the second compound, e.g. where administration of thefirst compound begins before the administration of the second compoundand the administration of the first compound ends before theadministration of the second compound ends; where the administration ofthe second compound begins before the administration of the firstcompound and the administration of the second compound ends before theadministration of the first compound ends; where the administration ofthe first compound begins before administration of the second compoundbegins and the administration of the second compound ends before theadministration of the first compound ends; where the administration ofthe second compound begins before administration of the first compoundbegins and the administration of the first compound ends before theadministration of the second compound ends. As such, “in combination”can also refer to regimen involving administration of two or morecompounds. “In combination with” as used herein also refers toadministration of two or more compounds that can be administered in thesame or different formulations, by the same of different routes, and inthe same or different dosage form type.

Individuals to be Treated

Individuals suitable for treatment with a subject anti-C1s antibodyinclude individuals who have been diagnosed as having acomplement-mediated disease or disorder; individuals at greater riskthan the general population for developing a complement-mediated diseaseor disorder (e.g., individuals having a genetic predisposition todeveloping a complement-mediated disease or disorder); individuals withParkinson's disease with dementia (PDD); individuals with Alzheimer'sdisease; and the like. In some cases, the individual is an adult human.In some cases, the adult human is 20 years or older, 30 years of age orolder; 40 years of age or older, 50 years of age or older, 60 years ofage or older, 70 years of age or older, or 80 years of age or older. Forexample, the adult human can be from 20 years old to 30 years old, from30 years old to 40 years old, 40 years old to 50 years old, from 50years old to 60 years old, from 60 years old to 70 years old, or olderthan 70 years. In some cases, the individual is a human child. In somecases, the human child is less than 20 years old, less than 10 yearsold, or less than 5 years old.

In Vitro Testing and Animal Models

The present disclosure provides a method to test the efficacy of asubject antibody in vitro or in vivo. In vitro testing includes methodsto assay the binding of a subject antibody to a complement C1s protein,methods to assay the ability of a subject antibody to inhibit productionof C4b2a complex, methods to identify the epitope, or characteristics ofthe epitope, to which an anti-C1s antibody of the present disclosurebinds. Non-human animal models to test the efficacy of a subjectantibody include experimental autoimmune encephalomyelitis (see, e.g.,Weerth et al., Am J. Path. 163:1069-1080 (2003); Theien et al., J. Clin.Invest. 107:995-1006 (2001)), myasthenia gravis (see, e.g., Morgan etal., Clin. Exp. Immun. 146:294-302 (2006)), myocardial ischemia andreperfusion (see, e.g., Busche et al., GMS Ger. Med. Sci. 8:Doc20(2010)), and Streptococcus pneumonia (see, e.g., Brown et al., Proc.Natl. Acad. Sci. 99:16969-16974)) models. Also suitable are non-humananimal models of transplant rejection (see, e.g., Racki et al. (2010)Transplantation 89:527; and Baldwin et al. (2010) Am. J. Transplantation10:1135). In some embodiments, the models are murine (e.g., rat ormouse) models. Such models are known to those skilled in the art.

Detection Methods

The present disclosure provides in vitro methods of detecting acomplement C1s protein in a biological sample obtained from anindividual; and methods of detecting a C1s protein in a livingindividual in vivo. A subject in vitro detection method can bequantitative. C1s protein or can thus serve as a biomarker forprogression of a complement-mediated disease or disorder, or response totreatment for a complement-mediated disease or disorder.

The Complement C1s protein that is detected/quantitated can befull-length C1s protein or any fragment thereof that comprises theepitope to which an anti-C1s antibody of the present disclosure binds.

Suitable biological samples include, but are not limited to, blood,serum, plasma, urine, saliva, cerebrospinal fluid, interstitial fluid,ocular fluid, synovial fluid, solid tissue sample, tissue culturesample, cellular sample, and other biological samples known to thoseskilled in the art.

An in vitro method of the present disclosure of detecting a complementC1s protein in a biological sample obtained from an individual generallyinvolves: a) contacting the biological sample with an anti-C1s antibodyof the present disclosure; and b) detecting binding of the antibody toC1s protein present in the sample.

A detection method of the present disclosure can be used to determinewhether an individual has, or is at risk of developing,complement-mediated disease or disorder. A detection method of thepresent disclosure can be used to determine the stage (severity) of acomplement-mediated disease or disorder. A detection method of thepresent disclosure can be used to monitor progression of acomplement-mediated disease or disorder in an individual. A detectionmethod of the present disclosure can be used to determine anindividual's response to a treatment regimen for treating acomplement-mediated disease or disorder. A biological sample can betested using a subject detection method, where the biological sample isobtained from an individual suspected of having a complement-mediateddisease or disorder, an individual who has been diagnosed as having acomplement-mediated disease or disorder, an individual who has a geneticpredisposition to developing a complement-mediated disease or disorder,etc.

The present disclosure provides a method of diagnosing acomplement-mediated disease or disorder in an individual. The methodgenerally involves (a) determining the amount of a complement C1sprotein in a biological sample obtained from the individual; and (b)comparing the amount of the complement C1s protein in the biologicalsample to a reference, a standard, or a normal control value thatindicates the amount of Complement C1s protein in normal controlsubjects. A significant difference between the amount of C1s protein inthe biological sample and the normal control value indicates that theindividual has a complement-mediated disease or disorder. In someembodiments, the step of determining comprises contacting the biologicalsample with an anti-C1s antibody of the present disclosure andquantitating binding of the antibody to complement C1s protein presentin the sample.

The present disclosure provides a method of monitoring the progressionof a complement-mediated disease or disorder in an individual. Themethod generally involves comparing the amount of a complement C1sprotein in a biological sample obtained from the individual at a firsttime point with the amount of a complement C1s protein in a biologicalsample obtained from the individual at a second time point. A differencein the amount of complement C1s protein in a biological sample obtainedfrom the individual at a second time point, compared to the amount ofcomplement C1s protein in a biological sample obtained from theindividual at a first time point, can provide an indication as to: i)whether the complement-mediated disease or disorder is progressing orwhether progression of the disease has been reduced or halted; and/orii) how quickly the complement-mediated disease or disorder isprogressing; and/or iii) whether the individual is exhibiting abeneficial clinical response to treatment with a drug or other treatmentregimen for treating the complement-mediated disease or disorder. Insome embodiments, the steps of determining comprise contacting thebiological sample with an anti-C1s antibody of the present disclosureand quantitating binding of the antibody to complement C1s proteinpresent in the sample. In some embodiments, the step of comparingindicates if the disease or disorder is progressing.

The present disclosure provides a method of monitoring response totreatment of a complement-mediated disease or disorder in an individual.The method generally involves comparing the amount of a complement C1sprotein in a biological sample obtained from the individual at a firsttime point with the amount of a complement C1s protein in a biologicalsample obtained from the individual at a second time point. A differencein the amount of complement C1s protein in a biological sample obtainedfrom the individual at a second time point, compared to the amount ofcomplement C1s protein in a biological sample obtained from theindividual at a first time point, can provide an indication as towhether the individual is exhibiting a beneficial clinical response totreatment with a drug or other treatment regimen for treating thecomplement-mediated disease or disorder. In some embodiments, the stepsof determining comprise contacting the biological sample with ananti-C1s antibody of the present disclosure and quantitating binding ofthe antibody to complement C1s protein present in the sample. In someembodiments, the step of comparing indicates if progression of thedisease is reduced or halted.

The present disclosure provides a method of staging acomplement-mediated disease or disorder. For example, a subject methodcan provide for staging Alzheimer's disease. For example, the amount ofa complement C1s protein in a biological sample from a living individualcan provide an indication as to the Braak stage of AD. Braak and Braak(1995) Neurobiol. Aging 16:271. For example, the amount of a complementC1s protein in a biological sample from a living individual can providean indication as to whether the individual is in transentorhinal stagesI-II of AD; limbic stages III-IV of AD; or neocortical stages V-VI ofAD.

The amount of a complement C1s protein in a biological sample can beassessed by any suitable method known in the art. Suitable methodsinclude, but are not limited to, a protein (“Western”) blot,immunoprecipitation, enzyme-linked immunosorbent assay (ELISA),radioimmunoassay (RIA), fluorescent activated cell sorting (FACS),two-dimensional gel electrophoresis, mass spectroscopy (MS),matrix-assisted laser desorption/ionization-time of flight-MS(MALDI-TOF), surface-enhanced laser desorption ionization-time of flight(SELDI-TOF), high performance liquid chromatography (HPLC), fast proteinliquid chromatography (FPLC), multidimensional liquid chromatography(LC) followed by tandem mass spectrometry (MS/MS), and laserdensitometry.

The present disclosure provides a method of monitoring progression of acomplement-mediated disease or disorder in an individual, where themethod generally involves: a) determining a first amount of a complementC1s protein in a biological sample obtained from the individual at afirst time point; b) determining a second amount of a complement C1sprotein in a biological sample obtained from the individual at a secondtime point; and c) comparing the second amount of complement C1s proteinwith the first amount of complement C1s protein. In some embodiments,the determining steps comprise: i) contacting the biological sample witha subject anti-C1s antibody; and ii) quantitating binding of theantibody to complement C1s protein present in the sample. In someembodiments, the comparison indicates if the disease has progressed.

In some cases, the first time point is a time point before initiation ofa treatment regimen, and the second time point is a time point afterinitiation of a treatment regimen. Thus, the instant disclosure providesa method of monitoring response to treatment with an agent that treats acomplement-mediated disease or disorder, where the method involves: a)determining a first amount of a complement C1s protein in a biologicalsample obtained from the individual at a first time point that is beforetreatment with an agent to treat a complement-mediated disease ordisorder is initiated; b) determining a second amount of a complementC1s protein in a biological sample obtained from the individual at asecond time point that is after initiation of treatment with an agent totreat a complement-mediated disease or disorder; and c) comparing thesecond amount of complement C1s protein with the first amount ofcomplement C1s protein.

A subject method of monitoring progression of a complement-mediateddisease or disorder can also be applied to methods of monitoringprogression of a tauopathy or synucleinopathy, e.g., Parkinson's disease(PD); dementia with Lewy Bodies (DLB); etc. For example, progression ofPD with dementia (PDD) can be monitored with a subject method.

A subject method can involve use of a kit or an assay device comprisinga subject anti-C1s antibody. The present disclosure provides kits andassay devices for carrying out a method as described herein. A subjectkit includes an anti-C1s antibody of the present disclosure.

An anti-C1s antibody can be immobilized on an insoluble support (e.g., atest strip, a well of a multi-well plate, a bead (e.g., a magneticbead), etc.). Suitable supports are well known in the art and comprise,inter alia, commercially available column materials, polystyrene beads,latex beads, magnetic beads, colloid metal particles, glass and/orsilicon chips and surfaces, nitrocellulose strips, nylon membranes,sheets, wells of reaction trays (e.g., multi-well plates), plastictubes, etc. A solid support can comprise any of a variety of substances,including, e.g., glass, polystyrene, polyvinyl chloride, polypropylene,polyethylene, polycarbonate, dextran, nylon, amylose, natural andmodified celluloses, polyacrylamides, agaroses, and magnetite. Suitablemethods for immobilizing a subject antibody onto a solid support arewell known and include, but are not limited to ionic, hydrophobic,covalent interactions and the like. Solid supports can be soluble orinsoluble, e.g., in aqueous solution. In some embodiments, a suitablesolid support is generally insoluble in an aqueous solution.

An anti-C1s antibody of the present disclosure can comprise a detectablelabel. Where the antibody comprises a detectable label, a subject kitcan include one or more reagents for developing the detectable label. Alabeled antibody can comprise a label such as a chemiluminescent agent,a particulate label, a colorimetric agent, an energy transfer agent, anenzyme, a fluorescent agent, or a radioisotope. Suitable detectablelabels include any composition detectable by spectroscopic,photochemical, biochemical, immunochemical, electrical, optical, orchemical means. Suitable detectable labels include, but are not limitedto, fluorescent labels (e.g., fluorescein isothiocyanate, texas red,rhodamine, a green fluorescent protein, a red fluorescent protein, ayellow fluorescent protein, and the like); radiolabels (e.g., ³H, ¹²⁵I,³⁵S, ¹⁴C, or ³²P); and enzymes (e.g., horse radish peroxidase, alkalinephosphatase, luciferase, and other enzymes that act on a substrate toproduce a product that can be detected by fluorometric, colorimetric, orspectrophotometric means).

In some cases, a method of the present disclosure fordetecting/quantitating C1s in a biological sample obtained from anindividual comprises treating the sample with a chelating agent, e.g., acalcium chelating agent, e.g., ethylenediaminetetraacetic acid (EDTA).The chelating agent disrupts a C1 complex, such that polypeptides thatform the C1 complex are separated from one another, generating monomericC1 complex components.

In some cases, a method of the present disclosure fordetecting/quantitating C1s in a biological sample obtained from anindividual comprises: a) contacting a biological sample with animmobilized first antibody that binds C1s but that does not compete witha subject anti-C1s antibody for binding to C1s (e.g., a rabbitpolyclonal antibody that binds C1s), forming an immobilized firstantibody/C1s complex; b) contacting the immobilized first antibody/C1scomplex with a chelating agent (e.g., EDTA), forming an immobilizedfirst antibody/C1s monomer complex; c) contacting the immobilized firstantibody/C1s monomer complex with a monoclonal anti-C1s antibody of thepresent disclosure; and d) detecting binding of the monoclonal anti-C1santibody to the immobilized C1s monomers. In some cases, a method of thepresent disclosure for detecting/quantitating C1s in a biological sampleobtained from an individual comprises: a) treating the biological samplewith a chelating agent (e.g., EDTA), forming C1s monomers; b) contactingthe chelating agent-treated biological sample with an immobilized firstantibody that binds C1s but that does not compete with a subjectanti-C1s antibody for binding to C1s (e.g., a rabbit polyclonal antibodythat binds C1s), forming an immobilized first antibody/C1s monomercomplex; c) contacting the immobilized first antibody/C1s monomercomplex with a monoclonal anti-C1s antibody of the present disclosure;and d) detecting binding of the monoclonal anti-C1s antibody to theimmobilized C1s monomers. Detection of binding of the monoclonalanti-C1s antibody to the immobilized C1s monomers can be accomplished invarious ways. For example, where the monoclonal anti-C1s antibodycomprises a detectable label, the detectable label is detected usingmethods appropriate to the label. Alternatively, the monoclonal anti-C1santibody can be detected using a detectably-labeled secondary antibodythat binds the monoclonal anti-C1s antibody. A subject kit can comprisea subject monoclonal anti-C1s antibody; and can further comprise one ormore of: 1) a chelating agent (e.g., EDTA); and 2) an anti-C1s antibodythat does not compete with a subject anti-C1s antibody for binding toC1s (e.g., a polyclonal anti-C1s antibody, such as a rabbit polyclonalantibody).

A subject kit can further include one or more additional components,where suitable additional components include: 1) a positive control; 2)a buffer (e.g., a binding buffer; a wash buffer; etc.); 3) reagents foruse in generating a detectable signal; and the like. Other optionalcomponents of the kit include: a protease inhibitor; a detectable label;etc. The various components of the kit can be present in separatecontainers or certain compatible components can be pre-combined into asingle container, as desired.

In addition to above-mentioned components, a subject kit can includeinstructions for using the components of the kit to practice a subjectmethod. The instructions for practicing a subject method are generallyrecorded on a suitable recording medium. For example, the instructionscan be printed on a substrate, such as paper or plastic, etc. As such,the instructions can be present in the kits as a package insert, in thelabeling of the container of the kit or components thereof (i.e.,associated with the packaging or subpackaging) etc. In otherembodiments, the instructions are present as an electronic storage datafile present on a suitable computer readable storage medium, e.g.compact disc-read only memory (CD-ROM), digital versatile disk (DVD),diskette, etc. In yet other embodiments, the actual instructions are notpresent in the kit, but means for obtaining the instructions from aremote source, e.g. via the internet, are provided. An example of thisembodiment is a kit that includes a web address where the instructionscan be viewed and/or from which the instructions can be downloaded. Aswith the instructions, this means for obtaining the instructions isrecorded on a suitable substrate.

An assay device can include a subject anti-C1s antibody immobilized on asolid substrate. The assay device can be in any of a variety of formats,e.g., a test strip, a dipstick; etc.

In Vivo Imaging

As discussed above, the present disclosure provides a method ofdetecting a complement C1s protein in a living individual, e.g., by anin vivo imaging technique. For example, in one embodiment, in vivoimaging of a C1s protein can be accomplished by positron emissiontomography (PET), single photon emission tomography (SPECT), nearinfrared (NIR) optical imaging, or magnetic resonance imaging (MRI). Insome embodiments, in vivo imaging is conducted using an IVIS®instrument, such as an IVIS® Spectrum. A subject anti-C1s antibody isadministered to an individual, and the presence and/or amount of thecomplement C1s protein is detected. The anti-C1s antibody can comprise alabel suitable for use in PET, SPECT, NIR, MRI, or IVIS. Such labelsinclude a contrast agent or a radioisotope, where the contrast agent orradioisotope is one that is suitable for use in imaging, e.g., imagingprocedures carried out on humans, as described above.

Generating a Report

In some instances, a subject detection method comprises detecting acomplement C1s protein in a biological sample obtained from anindividual; and, based on the amount of detected complement C1s protein,generating a report and/or directing therapy or management of theindividual from whom the biological sample was obtained.

A report can include one or more of: an indication as to whether theindividual likely has a complement-mediated disease or disorder; anindication of the severity of the complement-mediated disease ordisorder; an indication as to whether the individual exhibits abeneficial clinical response to treatment for the complement-mediateddisease or disorder; and the like.

Thus, a report can include information such as a predicted likelihoodthat the individual has, or will develop, a complement-mediated diseaseor disorder; a recommendation regarding further evaluation; arecommendation regarding therapeutic drug and/or other health managementintervention; and the like.

For example, the methods disclosed herein can further include a step ofgenerating or outputting a report providing the results of a subjectassessment, which report can be provided in the form of an electronicmedium (e.g., an electronic display on a computer monitor), or in theform of a tangible medium (e.g., a report printed on paper or othertangible medium). An assessment as to the likelihood that a person has,or is at risk of developing, a complement-mediated disease or disordercan be referred to as a “risk report,” “a risk score,” or “a likelihoodscore.” A person or entity that prepares a report (“report generator”)can also perform steps such as sample gathering, sample processing, andthe like. Alternatively, an entity other than the report generator canperform steps such as sample gathering, sample processing, and the like.A risk assessment report can be provided to a user. A “user” can be ahealth professional (e.g., a clinician, a laboratory technician, or aphysician).

Directing Health Management

In some instances, a subject detection method comprises detecting acomplement C1s protein in a biological sample obtained from anindividual; and, based on the amount of detected complement C1s protein,generating a report and/or directing therapy or management of theindividual from whom the biological sample was obtained.

Thus, e.g., depending on the outcome of a subject detection method, arecommendation can be made that the individual undergo therapeuticintervention (treatment) for the complement-mediated disease or disorderand/or that the individual be considered for special health management.Therapeutic intervention can include, e.g., drug therapy for thetreatment of Alzheimer's disease. Examples of drug therapy for thetreatment of Alzheimer's disease include, but are not limited to,acetylcholinesterase inhibitors, including, but not limited to, Aricept(donepezil), Exelon (rivastigmine), metrifonate, and tacrine (Cognex);an anti-Aβ antibody (e.g., solanezumab); an anti-C1s antibody;non-steroidal anti-inflammatory agents, including, but not limited to,ibuprofen and indomethacin; cyclooxygenase-2 (Cox2) inhibitors such asCelebrex; and monoamine oxidase inhibitors, such as Selegilene (Eldeprylor Deprenyl). Dosages for each of the above agents are known in the art.For example, Aricept can be administered at 50 mg orally per day for 6weeks, and, if well tolerated by the individual, at 10 mg per daythereafter.

Organ Preservation and Perfusion

The present disclosure provides compositions and methods for organpreservation and perfusion.

Compositions

The present disclosure provides a composition comprising an anti-C1santibody of the present disclosure. Such compositions can includepharmaceutically acceptable excipients.

The composition can include one or more agents for perfusion into anorgan or tissue. A perfusion composition can be used, e.g., for in situor ex vivo perfusion of a tissue or organ. Where perfusion is performedin situ, the donor individual is usually not an alive and healthyindividual.

The composition can include one or more agents that maintain an organ ora tissue intended for transplantation into a recipient individual. Apreservation composition can be used, e.g., for ex vivo preservation ofa tissue or organ.

For example, a tissue or organ obtained or to be obtained from a donorindividual is perfused with a perfusion solution in situ or ex vivo atthe time of or after removal from a donor individual. The tissue ororgan can be stored in a preservation solution ex vivo for a period oftime before the tissue or organ is transplanted into a recipientindividual. In some cases, the perfusion composition and thepreservation composition are the same.

In some cases, a subject composition is an aqueous solution thatcomprises: (a) an anti-C1s antibody of the present disclosure; and (b)one or more of: (i) a salt; (ii) an agent that reduces edema; (iii) anagent that scavenges free radicals (an “oxygen free radical inhibitor”or an “oxygen free radical scavenger”); and (iv) an energy supply systemcomponent. In some cases, a subject composition is an aqueous solutionthat comprises: (a) an anti-C1s antibody of the present disclosure; and(b) one or more of: (i) a saccharide (e.g., a monosaccharide, adisaccharide, a trisaccharide, a polysaccharide); and (ii) an agenthaving pH buffering properties; and, optionally, (c) one or more of:(iii) a calcium transport blocker; (iv) a thromboxane inhibitor; (v) acalcium chelating agent; and (vi) an iron chelating agent.

Suitable saccharides include, but are not limited to, sucrose,raffinose, and mannitol. Suitable pH buffer agents include a sodiumphosphate buffer, a potassium phosphate buffer, and the like; e.g.,Na₂PO₄, NaH₂PO₄, K₂PO₄, KH₂PO₄, and the like.

Suitable oxygen free radical scavengers include, but are not limited to,allopurinol and reduced glutathione. A suitable energy supply systemcomponent includes adenosine (or adenosine triphosphate (ATP)).

Examples of suitable calcium chelators include citrate and ethyleneglycol tetraacetic acid (EGTA). An example of a suitable iron chelatoris ethylenediaminetetraacetic acid (EDTA).

Agents that reduce edema include impermeant anions and colloidal osmoticagents.

As used herein, the term “impermeant anion” refers to compounds thatcounteract swelling in organs that have been exposed to hypothermictemperatures. Examples of impermeant anions include, but are not limitedto, gluconate and lactobionic acid.

Agents that reduce edema include a colloidal osmotic agent, e.g.,poly(ethylene glycol) (PEG), succinylated gelatin, Ficoll (apolysaccharide), or a starch product (e.g., hydroxyethyl starch).

In some cases, a subject composition also includes an amino acid, e.g.,glutamine, glycine, or N-acetylcysteine.

In some cases, a subject composition also includes an antimicrobialagent, e.g., an antibiotic, an anti-fungal agent, and the like.

A subject composition can include inorganic or organic solutes. Asuitable inorganic solute is an electrolyte including cations and/oranions, for example selected from Na⁺, K⁺, Cl⁻, OH⁻, Ca²⁺, Mg²⁺, and thelike. Electrolytes can be present at a concentration of, e.g.: (i) Na⁺,from about 50 mmol/L to about 150 mmol/L; (ii) K⁺, from about 0 mmol/Lto about 25 mmol/L; (iii) Cl⁻, from about 0 mmol/L to about 100 mmol/L;(iv) OH⁻, from about 0 mmol/L to about 75 mmol/L; (v) Ca²⁺, from about 0mmol/L to about 2 mmol/L; (vi) Mg²⁺, from about 0 mmol/L to about 10mmol/L.

The osmolality of a subject composition can range from about 300 mosmollto about 450 mosmol/l, e.g., from about 300 mosmol/l to about 325mosmol/l, from about 325 mosmol/l to about 350 mosmol/l, from about 350mosmol/l to about 375 mosmol/l, from about 375 mosmol/l to about 400mosmol/l, from about 400 mosmol/l to about 425 mosmol/l, or from about425 mosmol/l to about 450 mosmol/l.

The pH of a subject composition can range from about 6.9 to about 7.8,e.g., a subject composition can have a pH of 6.9, 7.0, 7.1, 7.2, 7.3,7.4, 7.5, 7.6, 7.7, 7.8, or 7.9.

In some cases, a subject composition is an aqueous solution thatcomprises: (a) an anti-C1s antibody of the present disclosure; and (b)one or more of: (i) hydroxyethyl starch; (ii) lactobionic acid; and(iii) raffinose.

In some cases, a subject composition is an aqueous solution thatcomprises: (a) an anti-C1s antibody of the present disclosure; (b)potassium lactobionate (100 mmol); (c) KH₂PO₄ (25 mmol); (d) MgSO₄ (4 5mmol); (e) raffinose (30 mmol); (f) adenosine (5 mmol); (g) glutathione(3 mmol); (h) insulin (100 Units); (i) a broad-spectrum antibiotic suchas trimethoprim (16 mg/mL); j) dexamethasone (8 mg/L); k) allopurinol (1mM); and 1) hydroxyethyl starch (e.g., hydroxyethyl starch) having amolecular weight of about 200,000 daltons to about 300,000 daltons and adegree of substitution of from about 0.4 to 0) (50 g/L).

In some cases, a subject composition is an aqueous solution thatcomprises: (a) an anti-C1s antibody of the present disclosure; and oneor more of: (i) hydroxyethyl starch (30 g/L to 100 g/L); (ii) NaCl (85mM to 145 mM); (iii) KCl (3 mM to 6 mM); (iv) CaCl₂ (1.0 mM to 1.6 mM);(v) KH₂PO₄ (0.7 mM to 1.3 mM); (vi) MgSO₄ (0.9 mM to 1.5 mM); (vii)allopurinol (0.05 mM to 5.0 mM); (viii) desferrioxamine (0.02 mM to 2.0mM); (ix) glutathione (0.5 mM to 10.0 mM); (x) nicardipene (0.1 μM to5.0 μM); (xi) adenosine (0.1 mM to 5.0 mM); (xii) fructose (1.0 mM to50.0 mM); (xiii) glucose (1.0 mM to 50.0 mM); (xiv) insulin (5 U/L to250 U/L); (xv) 3-(N-morpholino)propanesulfonic acid (MOPS) (2 mM to 40mM).

In some cases, a subject composition comprises:

(a) an anti-C1s antibody of the present disclosure;

(b) potassium lactobionate (e.g., 100 mM);

(c) KH₂PO₄ (e.g., 5 mM);

(d) raffinose (e.g., 30 mM);

(e) adenosine (e.g., 5 mM);

(f) glutathione (e.g., 3 mM);

(g) allopurinol (e.g., 1 mM); and

(h) hydroxyethyl starch (e.g., 50 g/L).

A subject anti-C1s antibody is present in a subject tissue/organpreservation or perfusion solution in an effective amount. An “effectiveamount” of a subject anti-C1s antibody is an amount that inhibitsproduction of C4b2a complex by at least 10%, at least 20%, at least 30%,at least 40%, at least 50%, at least 60%, at least 65%, at least 70%, atleast 75%, at least 80%, at least 85%, at least 90%, at least 95%, or100%, compared to the level of C4b2a in the absence of the anti-C1santibody. The concentration of the anti-C1s antibody in the compositioncan range from about 1 mg/mL to about 200 mg/mL, e.g., from about 1mg/mL to about 5 mg/mL, from about 5 mg/mL to about 10 mg/mL, from about10 mg/mL to about 25 mg/mL, from about 25 mg/mL to about 50 mg/mL, fromabout 50 mg/mL to about 100 mg/mL, or from about 100 mg/mL to about 150mg/mL.

The present disclosure provides an isolated (e.g., ex vivo) organ ortissue present in a preservation/perfusion solution as described above.

Methods of Organ Perfusion and Methods of Organ Preservation

The present disclosure provides methods of tissue or organ perfusion, aswell as methods of ex vivo tissue or organ preservation using acomposition comprising an anti-C1s antibody as described herein.

Perfusion methods generally involve introducing a perfusion solutioncomprising an anti-C1s antibody of the present disclosure into and/oraround a donor tissue or donor organ in situ or ex vivo in an amountsufficient to perfuse the tissue or organ with the perfusion solution.Where perfusion is performed in situ, the donor individual is usuallynot an alive and healthy individual. Perfusion can be accomplished by,for example, introducing a perfusion solution of the present disclosureinto a vascular bed of the tissue or organ. Perfusion can be performedso as to flush the tissue or organ with the perfusion solution, e.g., toat least partially displace blood present in the vasculature.

Preservation methods generally involve introducing a preservationsolution comprising an anti-C1s antibody of the present disclosure intoand/or around a donor tissue or organ ex vivo in an amount sufficient tomaintain the tissue or organ for later use, e.g., for use in transplant.

Perfusion and preservation methods described herein in general providefor inhibition of complement activation in the tissue or organ. Thus,the present disclosure provides a method for inhibiting complementactivation in a tissue or organ, the method involving introducing aperfusion or preservation solution as described herein into or around atissue or organ in situ or ex vivo, where the perfusion or preservationsolution is introduced in an amount sufficient to inhibit complementactivation in the tissue or organ.

Organs and tissues that can be preserved using a subject method include,but are not limited to, a kidney, a liver, a pancreas, a heart, a lung,skin, blood tissue (including whole blood; red blood cells; white bloodcells; cord blood; and the like, where the blood tissue may comprise anisolated population of blood cells (buffy coat; red blood cells;platelets; lymphocytes; T cells; B cells; or some other population), orwhere the blood tissue comprises a mixed population of cells), smallintestine, an endothelial tissue, a vascular tissue (e.g., a bloodvessel), an eye, a stomach, a thymus, bone, bone marrow, cornea, a heartvalve, an islet of Langerhans, or a tendon. As used herein, “organ”encompasses a whole organ or a part of an organ. As used herein,“tissue” encompasses a whole tissue or part of a tissue.

The organ or tissue can be of human origin. The organ or tissue can beof non-human animal (e.g., porcine) origin. In some cases, the tissue ororgan is an allograft, i.e., the tissue or organ is allogeneic to aprospective recipient. In some cases, the tissue or organ is axenograft, i.e., the tissue or organ is from a xenogeneic sourcerelative to a prospective recipient. The organ or tissue can be obtainedfrom a living individual, or from a recently deceased individual (e.g.,where the organ or tissue is obtained from an individual within about 1minute or a few hours following death of the individual).

An organ or tissue can be stored in a subject preservation or perfusionsolution at a hypothermic temperature, or at a normothermic temperature.For example, an organ or tissue can be stored in a subject preservationor perfusion solution at a hypothermic temperature of from about 1° C.to about 10° C. As another example, an organ or tissue can be stored ina subject preservation or perfusion solution at a normothermictemperature of from about 12° C. to about 24° C.

An organ or tissue can be stored in a subject preservation or perfusionsolution for a period of time of from about 1 minute to about 24 hours,e.g., from about 1 minute to about 15 minutes, from about 15 minutes toabout 30 minutes, from about 30 minutes to about 1 hour, from about 1hour to about 4 hours, from about 4 hours to about 8 hours, from about 8hours to about 12 hours, or from about 12 hours to about 24 hours. Insome cases, an organ or tissue can be stored in a subject preservationor perfusion solution for a period of time of longer than 24 hours. Anorgan or tissue can be perfused with a subject preservation or perfusionsolution for a period of time of from about 1 minute to about 24 hours,e.g., from about 1 minute to about 15 minutes, from about 15 minutes toabout 30 minutes, from about 30 minutes to about 1 hour, from about 1hour to about 4 hours, from about 4 hours to about 8 hours, from about 8hours to about 12 hours, or from about 12 hours to about 24 hours.

Tables 2 and 3 provide a listing of the SEQ ID NOs disclosed in theapplication. FIG. 2 provides Table 2. Table 3 is provided below. It isto be appreciated that since nucleic acid sequencing technology is notentirely error-free, the nucleic acid sequences and amino acid sequencespresented herein represent, respectively, apparent nucleic acidsequences of nucleic acid molecules of the embodiments and apparentamino acid sequences of proteins of the embodiments.

TABLE 3 Listing of non-antibody amino acid sequences disclosed herein.SEQ ID NO: Source Description/Sequence  9 Homo sapiensHuman complement C1s protein; sequence depicted in FIG. 1 10 Synthetic(GSGGS)_(n) 11 Synthetic (GGGS)_(n) 12 Synthetic GGSG 13 Synthetic GGSGG14 Synthetic GSGSG 15 Synthetic GSGGG 16 Synthetic GGGSG 17 SyntheticGSSSG 18 Synthetic YPYDVPDYA 19 Synthetic DYKDDDDK 20 SyntheticEQKLISEEDL 21 Synthetic HHHHH 22 Synthetic HHHHHH 23 Synthetic WSHPQFEK24 Synthetic RYIRS 25 Synthetic FHHT 26 Synthetic WEAAAREACCRECCARA 27Synthetic TFFYGGCRGKRNNFKTEEY 28 Synthetic TFFYGGSRGKRNNFKTEEY 29Synthetic CTFFYGGSRGKRNNFKTEEY 30 Synthetic TFFYGGSRGKRNNFKTEEYC 31Synthetic TFVYGGCRAKRNNFKS

EXAMPLES

The following examples are put forth so as to provide those of ordinaryskill in the art with a complete disclosure and description of how tomake and use the present invention, and are not intended to limit thescope of what the inventors regard as their invention nor are theyintended to represent that the experiments below are all or the onlyexperiments performed. Efforts have been made to ensure accuracy withrespect to numbers used (e.g. amounts, temperature, etc.) but someexperimental errors and deviations should be accounted for. Unlessindicated otherwise, parts are parts by weight, molecular weight isweight average molecular weight, temperature is in degrees Celsius, andpressure is at or near atmospheric. Standard abbreviations can be used,e.g., bp, base pair(s); kb, kilobase(s); pl, picoliter(s); s or sec,second(s); min, minute(s); h or hr, hour(s); aa, amino acid(s); kb,kilobase(s); bp, base pair(s); nt, nucleotide(s); i.m.,intramuscular(ly); i.p., intraperitoneal(ly); s.c., subcutaneous(ly);and the like.

Example 1 Production and Characterization of Anti-Complement C1s IPN003Antibody

Anti-C1s monoclonal antibody IPN003 (also referred to as “IPN-M34” or“M34”) was produced as follows: Immunization of BALB/c and NZBW micewith purified human activated C1s protein, two-chain form (EMDMillipore, Billerica, Mass.) (SEQ ID NO:9) generated two independenthybridoma libraries which were screened with C1s protein usingtechniques known to those skilled in the art (see, e.g., Galfre et al.,Methods in Enzymology 73:346 (1981). Flow cytometry was used to generatesingle cell clones, and supernatants from these individual clones werescreened for binding to biotin-labeled activated C1s using a solutionphase monoclonal antibody capture assay, such as that disclosed, e.g.,in Nix et al., in Immunoassays, A Practical Approach, editor J. P.Gosling, pp. 239-261, Oxford University Press (2000). One hundredseventy-one clones bound activated C1s with high affinity. One of theclones isolated from NZBW mice that bound activated C1s produced anantibody denoted IPN003 (or IPN-M34; or M34; or TNT003).

Amino acid sequencing of the VH and VL regions of IPN003 anti-C1santibody was conducted using techniques known to those skilled in theart (MCLAB, South San Francisco, Calif.). Specifically, cell pelletswere prepared from the hydridoma cell line expressing the IPN003monoclonal antibody, and RNA was extracted using an RNAqueous®-4PCR kit(Life Technologies Inc., Grand Island, N.Y.). V-regions were amplifiedby reverse transcription-polymerase chain reaction (RT-PCR) usingdegenerate primer pools for murine antibody signal sequences togetherwith constant region primers for IgMVH, IgGVH, IgκVL and IgλVL. Thepolymerase chain reaction (PCR) products obtained from each of thesuccessful amplifications were purified and cloned into a ‘TA’ cloningvector (pGEM-T® Easy, Promega, Madison, Wis.) from which sequences wereobtained. The deduced amino acid sequences of the VH and VL regions ofthe IPN-M34 antibody are provided in Table 2. Also provided in Table 2(FIG. 2) are the CDRs of IPN003.

Example 2 Binding Characteristics of IPN003

IPN003 binding characteristics were compared to those of M81. For M81,see, e.g., Matsumoto et al. (1986) J. Immunol. 137:2907; Matsumoto etal. (1989) J. Immunol. 142:2743; and Nakagawa et al. (1999) Ann. Rheum.Dis. 58:175.

IPN003 Competes with M81 for Binding to Human C1s.

To determine if IPN003 could compete binding of M81 to human C1s,competition assays were performed, in which biotin-labeled M81 (finalconcentration 0.5E-9 M) was incubated with increasing concentrations ofunlabeled antibodies in wells coated with human C1s. The data are shownin FIG. 3.

Unlabeled M81 competed binding of labeled M81 with an IC₅₀ of 3E-9 M,whereas a control antibody did not compete. As shown in FIG. 3, IPN003(M34) competed binding of M81 to human C1s. IPN003 was a more potentinhibitor of M81 binding (IC₅₀ of 0.33E-9 M) than M81, suggesting thatthe epitope of IPN003 is distinct from, but overlapping with, theepitope recognized by M81.

IPN003 Inhibits Human C1s Activation of Human C4.

Human complement protein C4 was incubated with activated human C1s inthe presence of increasing concentrations of monoclonal antibodies M81or IPN003. As shown in FIG. 4, the data demonstrate that IPN003 inhibitsC1s mediated activation of human complement protein C4. IPN003 inhibitedactivation of C4 with an IC₅₀ of 3E-9 M. In contrast, M81 was a muchless potent inhibitor and inhibited C4 activation with an IC₅₀ of 55E-9M.

IPN003 Inhibits Human Complement Mediated Cell Lysis.

The ability of IPN003 to inhibit complement-mediated cell lysis wasmeasured in a standard sheep red blood cell (sRBC) hemolysis assay usinghuman serum as a source of complement proteins. The data are shown inFIG. 5.

A control IgG had no effect on cell lysis, whereas IPN003 inhibited celllysis with an IC₅₀ of 1.1E-9 M. In contrast, M81 was a much less potentinhibitor than IPN003, and inhibited sRBC lysis with an IC₅₀ of 11.3E-9M. Thus, the data presented in FIG. 5 show that IPN003 can inhibitactivation of the intact classical complement cascade using a standardhemolysis assay; and that IPN003 is significantly more active than M81,consistent with the data presented in FIGS. 3 and 4.

IPN003 Inhibits Cell Lysis Mediated by Macaca fascicularis Complementand by Macaca mulatta Complement.

To determine whether IPN003 could inhibit complement-mediated cell lysisin a species suitable for toxicology studies, hemolysis assays wereperformed in which complement proteins were provided by serum fromMacaca fascicularis and from Macaca mulatta, two monkey species that areconsidered suitable for toxicology studies. The data are shown in FIGS.6 and 7.

As shown in FIG. 6, IPN003 inhibited cell lysis, mediated by serum fromMacaca fascicularis, with an IC₅₀ of 4.6E-9 M. In contrast M81 was amuch less potent inhibitor and inhibited sRBC lysis with an IC₅₀ of189E-9 M.

As shown in FIG. 7, IPN003 inhibited cell lysis, mediated by serum fromMacaca mulatta, with an IC₅₀ of 4.5E-9 M. In contrast M81 was a muchless potent inhibitor and inhibited sRBC lysis with an IC₅₀ of 83E-9 M.

The data presented in FIGS. 6 and 7 also strongly suggest that IPN003cross-reacts with C1s from at least two monkey species. The data alsoindicate that IPN003 is a more potent inhibitor of complement activationthan M81.

IPN003 is Specific for the C1s Component of the Complement Cascade.

To determine whether IPN003 could bind other components of thecomplement cascade, ELISA assays were performed with target proteinsimmobilized on micro-titer plates. The data, shown in FIG. 8,demonstrate that IPN003 is specific for C1s and does not bind to othercomponents of the complement pathway.

Table 4 (provided in FIG. 9) summarizes the binding characteristics ofIPN003.

IPN003 Binds Rat C1s

ELISA assays were performed with purified rat C1s immobilized onmicro-titer plates and increasing dilutions of IPN003 or M81. The data,presented in FIG. 10, show that IPN003 bound rat C1s with a K_(D) of0.2E-9 M whereas M81 bound rat C1s with a K_(D) of 0.8E-9 M.

Example 3 Inhibition by IPN003 of rat C1s-Mediated Cleavage of Human C4

Human C4 (0.25 mg/ml) was incubated at 37° C. with rat C1s (0.64 μg/ml),with various concentrations of IPN003. Samples containing the reactionproducts were reduced; the reduced samples were separated on a 4-12%NuPAGE gel; and the gel was stained with Coomassie blue. The C4acleavage product band on the Coomassie gel was quantitated on a Licorscanner. The results are shown in FIG. 11. As shown in FIG. 11, IPN003inhibits rat C1s-mediated cleavage of human C4 in aconcentration-dependent manner, with an IC₅₀ of 1.47 μg/ml.

A comparison of IPN003 inhibition of rat C1s-mediated and humanC1s-mediated cleavage of human C4 was carried out. 5 μl rat C1s (0.64μg/ml) or 5 μl human C1s (0.2 μg/ml) was added to 5 μl of 1 mg/ml IPN003or an irrelevant control IgG; and the mixture kept for 30 minutes atroom temperature. Following incubation, 10 μl of 1 mg/ml human C4 wasadded; this mixture was incubated at 37° C. for 80 minutes. Samplescontaining the reaction products were analyzed by Coomassie-stainedgels, and by ELISA. The results are shown in FIG. 12. As shown in FIG.12, IPN003 inhibits rat C1s-mediated cleavage of human C4 to a similardegree as IPN003 inhibits human C1s-mediated cleavage of human C4.

Example 4 IPN003 Inhibition of Patient Serum-Induced Human RBC Lysis andC3b Deposition

Assays were carried out to determine whether IPN003 inhibits autoimmunehemolytic anemia (AIHA) patient serum-induced human RBC lysis and C3bdeposition.

A sample containing 10 μl packed human RBC (hRBC) and 50 μl patientserum was incubated for 30 minutes at 30° C. Normal human serum servedas a control. After the 30-minute incubation, the sample was centrifugedand washed once. Then, complement competent human serum (12.5%) with orwithout IPN003 (100 μg/ml) was add to sensitized hRBC; and samples wereincubated for 1 hr at 37° C. After the one-hour incubation period, thesupernatants were collected, and absorbance at 540 nm measured. Theresults are shown in FIG. 13. The data presented in FIG. 13 show thatIPN003 inhibits hemolysis of hRBC pre-incubated in AIHA serum fromPatient P3-1. The background hemolysis mediated by human normal serum ismediated by a mechanism that is independent of complement.

Assays were carried out to determine whether IPN003 inhibits AIHApatient serum-induced C3b deposition on human RBCs. As shown in FIG. 14,IPN003 completely inhibits C3b deposition on hRBCs that were incubatedwith an AIHA serum sample (patient P3-1).

Example 5 Humanized IPN003 Variants

Humanized variants of IPN003 were generated. Amino acid sequences of theheavy chain VH domains of humanized variants 1-4, and nucleotidesequences encoding the heavy chain VH domain of the humanized variants,are shown in FIGS. 16-19. Amino acid sequences of the light chain VLdomain of humanized variants 1-3, and nucleotide sequences encoding thelight chain VL domain of the humanized variants, are shown in FIGS.20-22. Amino acid differences relative to the amino acid sequence ofIPN003 (VL SEQ ID NO:37; VH SEQ ID NO:38) are summarized in Tables 7 and8 (FIG. 23).

Single letter amino acid codes are as follows (with 3-letter amino acidcodes in parentheses):

G—Glycine (Gly)

P—Proline (Pro)

A—Alanine (Ala)

V—Valine (Val)

L—Leucine (Leu)

I—Isoleucine (Ile)

M—Methionine (Met)

C—Cysteine (Cys)

F—Phenylalanine (Phe)

Y—Tyrosine (Tyr)

W—Tryptophan (Trp)

H—Histidine (H is)

K—Lysine (Lys)

R—Arginine (Arg)

Q—Glutamine (Gin)

N—Asparagine (Asn)

E—Glutamic Acid (Glu)

D—Aspartic Acid (Asp)

S—Serine (Ser)

T—Threonine (Thr)

Example 6 Characterization of Humanized IPN003 Variants

The relative binding affinities for various humanized IPN003 variants toactivated C1s are shown in Table 9, which is presented in FIG. 24. Therelative binding affinities for various humanized IPN003 variants topro-C1s are shown in Table 10, which is presented in FIG. 24. Humanizedvariants bind active C1s with an approximately 2-fold higher affinitythan the parental IPN003 antibody. For comparison, the K_(D) (M) ofIPN003 to human C1s is 1.58E-9 to 2.04E-9; the K_(on) (1/Ms) is3.56E+05; and the K_(dis) (1/s) is 5.53E-04.

Humanized variants were generated, having an IgG4 constant region thatis hinge-stabilized (having an S241P substitution) and that has reducedeffector function (having an L235E substitution). All 24 combinations(VH variant 1+Vk variant 1; VH variant 1+Vk variant 2; VH variant 1+Vkvariant 3; VH variant 2+Vk variant 1; VH variant 2+Vk variant 2; VHvariant 2+Vk variant 3; VH variant 3+Vk variant 1; VH variant 3+Vkvariant 2; VH variant 3+Vk variant 3; VH variant 4+Vk variant 1; VHvariant 4+Vk variant 2; VH variant 4+Vk variant 3) were transientlyexpressed in HEK cells. Each humanized variant was tested for theability to compete with IPN003 for binding to C1s. The data are shown inFIG. 25.

Each humanized variant was tested in a commercially available assay thatmeasures complement classical pathway (CP) activation. The results areshown in FIG. 26. The data show that all 12 humanized variants inhibitCP activation with an IC₅₀ similar to that of IPN003.

As shown in FIGS. 27A and 27B, of the 3 humanized variants tested, allwere specific for the classical pathway. FIG. 27A showsconcentration-dependent inhibition of CP by humanized variants VH2/VK3,VH3/VK1, and VH4/VK2. IPN003 is shown for comparison. FIG. 27B shows theeffect of humanized variants VH2/VK3, VH3/VK1, and VH4/VK2 on thealternative pathway (AP).

Humanized variants were tested for inhibition of red blood cell (RBC)lysis, and inhibition of the deposition of C3b on RBCs. The data areshown in FIG. 28.

Example 7 Inhibition of Complement-Dependent Hemolysis

Assays were carried out to determine whether IPN003, or a humanizedvariant of IPN003, can inhibit cold agglutinin disease (CAD) patientplasma-induced human RBC lysis. Assays were also conducted to determinewhether IPN003, or a humanized variant of IPN003, can inhibitanaphylatoxin production.

Hemolysis assays were conducted essentially as described in Example 4.Type O⁻ normal human red blood cells were incubated in the presence ofcold agglutinin disease (CAD) patient plasma (CAD patient 5; “CAD P5”)at 4° C., allowing autoantibodies in the plasma to bind the RBC, therebygenerating sensitized hRBCs. 10 mM EDTA was added during sensitizationto prevent complement activation. After ˜½ hour, plasma was washed away,and 25% normal human serum containing active complement and antibody(IPN003, humanized variant of IPN003, or control IgG2a) was added. Afteraddition of the human serum and antibody to the sensitized hRBCs,samples were incubated for 1 hr at ˜18° C. After the one-hour incubationperiod, the supernatants were collected, and absorbance at 540 nmmeasured. The results are shown in FIG. 29.

As shown in FIG. 29, plasma of CAD patient P5 induced hRBC lysis. IPN003and a humanized variant of IPN003, but not control IgG2a, inhibitedcomplement-dependent CAD patient plasma-mediated hRBC hemolysis.Complement-dependent lysis was inhibited in a concentration-dependentmanner.

Anaphylatoxins C3a, C4a, and C5a generation was tested using the CAD P5supernatant from the above-described hemolysis experiment. The data areshown in FIG. 30. As shown in FIG. 30, IPN003 and a humanized variant ofIPN003 (hu-IPN003), but not control IgG2a, inhibited generation of allthree anaphylatoxins with similar efficacy (complete inhibition) andpotency (˜4.5-5.5 μg/mL) compared to hemolysis.

Example 8 Inhibition of C3b Deposition on Red Blood Cells

Four CAD patient plasma samples were tested for their ability to inhibitC3b deposition on hRBCs. Plasma samples from CAD patients P8, P11, P14,and P15 were incubated with IPN003 or control IgG2a; and the percent ofC3b-positive cells was determined using flow cytometry. The data areshown in FIGS. 31 and 32. As shown in FIG. 31, 100 μg/mL IPN003, but notcontrol IgG2a, significantly inhibited C3b deposition on the RBCsurface. The average inhibition was ˜90%. As shown in FIG. 32, CADplasma-mediated deposition of C3b on hRBCs was inhibited by IPN003, butnot by control IgG2a, in a concentration-dependent manner. The IC₅₀ forIPN003 was about 6.6 μg/ml.

Example 9 Immunogenic Potential of a Humanized Variant of IPN003

Humanized anti-C1s antibody was assessed for immunogenic potential. AnEpiScreen™ assay was used. See, e.g., Jones et al. (2004) J. InterferonCytokine Res. 24:560; and Jones et al. (2005) J. Thromb. Haemost. 3:991.Time course T cell assays were performed using CD8⁺-depleted peripheralblood mononuclear cells (PBMC); and T cell proliferation was measured byincorporation of [³H]-thymidine at various time points after addition oftest antibody samples. Proliferation responses to a humanized anti-C1santibody or a chimeric anti-C1s antibody are shown in FIGS. 33A and 33B.

As shown in FIG. 33A, a test fully humanized IPN003 antibody had lowimmunogenic potential (below the SI threshold of 2.0). FIG. 33B showsresults with a reference chimeric antibody, where the reference chimericantibody has IPN003 murine heavy and light chain variable regions andhuman IgG4 constant region.

Example 10 Effect of TNT003 on Complement-Dependent, CADAutoantibody-Mediated Activities

The effect of TNT003 on hemolysis, phagocytosis, and C4a generationmediated by autoantibodies present in sera of patients with coldagglutinin disease (CAD) was determined.

The data are shown in FIGS. 34-37.

As shown in FIG. 34, both TNT003 and an anti-C5 mAb prevent complementdependent CAD autoantibody-mediated hemolysis in aconcentration-dependent manner. In a 96-well plate, Type O⁻ red bloodcells were incubated in the presence of plasma from a CAD patient and 10mM EDTA to allow for autoantibody binding (45 minutes at 4° C.). Cellswere then washed with GVB++ (GVB with Ca++ and Mg++) buffer. GVB++buffer: 0.1% gelatin, 5 mM Veronal, 145 mM NaCl, 0.025% NaN₃, pH 7.3.Containing 0.15 mM calcium chloride and 0.5 mM magnesium chloride Freshnormal human serum (25% final concentration in GVB++) and varyingconcentrations of either TNT003 or an anti-C5 mAb were then added to thecells and allowed to incubate for 1 hr at 17° C. Following incubation,50 μL of GVB++ was added to each well to stop the reaction. The 96-wellplate was then centrifuged and a portion of the supernatant collectedand transferred to a new 96-well plate. Peak absorbance values (540 nm)were read on a microplate reader. A well that contained 10 mM EDTAinstead of antibody was used as a control well to determinenon-complement mediated hemolysis (positive control). The absorbancevalue from this well was subtracted from all other wells to determinethe extent of complement-dependent lysis. Similarly, a control wellwithout antibody was used to determine maximal complement dependenthemolysis (negative control).

As shown in FIG. 35, TNT003, but not an anti-C5 mAb nor a control mouseIgG2a antibody, inhibited C3b deposition mediated by CAD autoantibodies.In a 96-well plate, Type O⁻ red blood cells were incubated in thepresence of plasma and 10 mM EDTA from a CAD patient or healthy normalplasma (negative control) to allow for autoantibody binding (45 minutesat 4° C.). Cells were then washed with GVB++ buffer. Fresh normal humanserum (25% final concentration in GVB++) and 100 μg/mL of TNT003, amouse IgG2a control Ab, or an anti-C5 mAb were then added to the cellsand allowed to incubate for 1 hr at 17° C. Cells were then washed withFACS buffer (2×). FACS buffer: phosphate-buffered saline (PBS) w/o+0.5%bovine serum albumin (BSA)+0.1% NaN₃). FACS buffer is the buffer inwhich cells and antibodies are incubated prior to running in a flowcytometer. Cells were then incubated in the presence of a mouse antihuman C3b monoclonal antibody (1 hr, 4° C.). Cells were then washed withFACS buffer (3×) and incubated with a secondary antibody (Alexa Fluor488 conjugated goat anti-mouse IgG1) at room temperature for 30 minutes.Cells were then washed with FACS buffer (3×) and fluorescence read outat 488 nm on a flow cytometer.

As shown in FIG. 36, TNT003 prevented complement-mediated phagocytosisinduced by CAD autoantibodies. To understand the effect of CADautoantibody-mediated complement deposition on RBC phagocytosis, aphagocytosis assay was developed using the THP-1 monocytic cell line.Type O− human RBC were labeled with Cell Tracker Green and sensitizedwith CAD autoantibodies by incubating in the presence of CAD patientplasma and 10 mM EDTA overnight (4° C.). Following washout of CADplasma, normal human serum (NHS; final concentration 25%) and either 100μg/mL TNT003 or 100 μg/mL IgG2a control Ab was added (1 hr at 17° C.).Retinoic acid treated THP-1 cells (3 μM, 3 days) were then plated in a96 well plate (1×10^5 cells/well) and treated with FcX. FcX is a reagentused to prevent activation of FcgR, a potential confounding factor inthe phagocytosis assay as FcgR can mediate phagocytosis as well; see,e.g., www(dot)biolegend(dot)com. The hRBC were then added to the THP-1cells at 5×10^6 cells/well for 2 hr at 37° C. to allow for phagocytosis(red bars). Phagocytosis was determined by flow cytometer and expressedas a percentage of THP-1 cells containing Cell Tracker Green-labeledRBC. A portion of the hRBC was also taken to stain with an anti C3b Abto quantify C3b deposition by FACS analysis as described above (bluebars).

It was found that hRBC coated with CAD autoantibodies but not incubatedin the presence of NHS had very low levels of membrane bound C3b andwere not readily phagocytosed by THP-1 cells (No NHS). Upon exposure to25% NHS, C3b deposition increased ˜30 fold and phagocytosis by ˜5 fold(NHS). 100 μg/mL TNT003, but not IgG2a control antibody, inhibited bothC3b deposition and phagocytosis to baseline levels, providing evidencethat TNT003 can prevent CAD autoantibody-mediated RBC phagocytosis. Datapresented are the average of two independent experiments preformed withone patient sample (P18), and are representative of results generatedfrom 5 different CAD patient samples.

As shown in FIG. 37A and FIG. 37B, TNT003, but not an anti-C5 mAb,prevents C3a and C4a generation by CAD autoantibodies. As shown in FIG.37C, both TNT003 and an anti-C5 mAb are able to inhibit CADautoantibody-mediated C5a generation. Commercially available ELISA kitswere used to detect and quantify C3a, C4a, and C5a from the supernatantsof the experiments described above. C3a, C4a and C5a levels in the humanserum used as a complement source were subtracted as background.

Example 11 In Vivo Effects of TNT003

In vivo effects of TNT003 were tested in a non-human primate. The dataare shown in FIGS. 38 and 39.

As shown in FIG. 38, TNT003-containing sera from cynomolgus monkeysgiven a single i.v. dose of TNT003 (30 mg/kg) were unable to inducecomplement-dependent hemolysis or deposit C3b on the plasma membrane ofIgM-sensitized sheep red blood cells. Sera taken from monkeys before andafter i.v. injection at various time points were used as a source ofcomplement for inducing hemolysis of IgM-sensitized sheep red bloodcells. Final serum concentration was 1.25%. As depicted in FIG. 38A,immediately following i.v. injection of TNT003, sera samples obtainedfrom the monkeys were unable to hemolyse IgM-sensitized sheep red bloodcells in all samples containing detectable TNT003 levels (up to andincluding 72 hours; plotted on the right Y-axis). At 96 hours, TNT003fell below detectable levels (as determined by an ELISA capture assay;plotted on the left Y-axis) at which point serum hemolytic capacity wasrestored to pre-bleed levels. FACS assays designed to detect thepresence of membrane-bound C3b (FIG. 38B) show that TNT003 containingsera also fail to deposit C3b on the plasma membrane of IgM-sensitizedsheep red blood cells. These data suggest that TNT003 is present atefficacious levels following in vivo administration to inhibit theclassical complement pathway in ex vivo hemolysis assays.

As shown in FIG. 39, TNT003 inhibits in vivo C4a generation incynomolgus monkeys given a single i.v. dose of TNT003 (30 mg/kg). C4aconcentrations in serum samples taken from TNT003-dosed monkeys weredetermined using commercially available ELISA kits (plotted on the rightY-axis). The data show that C4a levels drop by approximately 90%immediately following TNT003 administration and remain low in allsamples containing detectable TNT003 (up to and including 72 hours). At96 hours, TNT003 fell below detectable levels (as determined by an ELISAcapture assay; plotted on the left Y-axis) at which point serum C4a wererestored to pre-bleed levels. These data provide evidence that TNT003 isactive in vivo and upon 30 mg/kg administration, reaches levels thatinhibit classical pathway activity in the cynomolgus monkey.

Example 12 TNT003 Epitope Mapping

To identify the minimal region of human C1s (hC1s) required for TNT003binding, full-length hC1s and N-terminal and C-terminal truncations ofhC1s were expressed in HEK293 cells. Recombinant proteins were purifiedby affinity chromatography and analyzed by western blots of non-reducedSDS-PAGE gels. As shown in FIG. 40, a fragment (hC1s fragment 1.b),consisting of amino acids 272-422 that specifically bound TNT003, wasidentified. Additional N-terminal and C-terminal truncations of thisamino acid fragment eliminated binding of TNT003.

FIG. 40. Identification of the minimal human C1s fragment required forTNT003 binding. Full-length or fragments of C1s were expressed in HEK293cells. Proteins were purified by affinity chromatography and analyzed bywestern blot of non-reduced SDS-PAGE gels with TNT003. TNT003 binds tofull-length C1s (Lane 3) and a fragment of C1s (fragment 1.b) containingamino acids 272-422 of the C1s A-chain.

To further identify the epitope of TNT003 in full-length human C1s,alanine scanning mutagenesis was performed using standard techniques.Mutation of amino acid 357 (aspartic acid) to alanine significantlydecreased binding of TNT003 to human C1s. Importantly, as shown in FIG.41, this mutation had no significant effect on the catalytic activity ofC1s and did not alter its ability to cleave its substrate, C4,suggesting that the protein was correctly folded. However, in contrastto its effect on wild-type C1s, TNT003 was unable to inhibit theactivity of this mutant C1s, even at high concentrations. Takentogether, these data suggest that the epitope of TNT003 containsaspartic acid 357 and that this amino acid is critical to the bindingand inhibitory activity of the antibody.

FIG. 41: Identification of a specific amino acid (aspartic acid 357)required for TNT003 binding to human C1s. Alanine scanning mutagenesisof human C1s was performed using standard techniques. Each C1s mutantprotein was expressed in HEK293 cells and purified by affinitychromatography. To measure enzymatic activity each mutant C1s proteinwas incubated with purified human C4 for 1 h at 37° C. in the presenceor absence of TNT003. Reactions were analyzed by SDS-PAGE to identify C4cleavage products (C4a and C4b). Mutation of aspartic acid 357eliminated the ability of TNT003 to inhibit C1s activity. In contrast,mutation of aspartic acid 343 to alanine had no effect on C1s enzymaticactivity, or the ability of TNT003 to inhibit

Example 13 TNT003 Avidity

TNT003 is a potent inhibitor of C1s activity both in purified systemsand in functional assays—for example red blood cell hemolysis. Theactivity of TNT003 was compared to other C1s antibodies in a plate basedC4 deposition assay (FIG. 42). TNT003 was a more potent inhibitor of C1sactivity than other anti-C1s antibodies (TNT004, TNT005, TNT006;anti-C1s antibodies that inhibit C1s protease activity)—even if theother anti-C1s antibodies bound to C1s with higher affinity. These datasuggested that the potency of TNT003 was mediated in part by its avidityfor C1s within the C1 complex and that a single molecule of TNT003 couldcontact (and therefore inhibit) both C1s molecules simultaneously.

FIG. 42: TNT003 is a potent inhibitor of human C1s activity. Wells of a96-well plate were coated with human IgM antibodies and non-specificbinding blocked using gelatin. Human serum (final concentration 1.25%)was added to the wells in the presence or absence of increasingconcentrations of antibody and incubated for 1 h at 37° C. The amount ofC4 deposited on the plate was measured using a biotinylated anti-humanC4 antibody and a streptavidin-HRP conjugate.

To demonstrate that TNT003 could bind the C1 complex, biotin-labeledTNT003 was incubated with purified C1 complex and the reaction wasfractionated on a Sepharose Superdex-200 column. As shown in FIG. 43B,C1 bound TNT003 to form a complex with a molecular weight consistentwith a single TNT003 antibody binding to each C1 complex.

FIGS. 43A and 43B: TNT003 binds to the C1 complex. TNT003 wasbiotin-labeled and incubated with purified human C1 complex. Thereaction was fractionated on a Sepharose Superdex-200 column and eachfraction analyzed for the presence of TNT003 by western blotting. Asshown in FIG. 43A, TNT003 alone eluted as a single peak. In contrast,following incubation with purified C1 complex, a second peak wasobserved, consistent with the formation of a TNT003:C1 complex (FIG.43B).

To further characterize the mechanism of inhibition, the ability ofTNT003, the TNT003 F(ab′)₂ fragment, and the TNT003 Fab fragment, toinhibit C1s activity was measured. As shown in FIG. 44, TNT003 and theTNT003 F(ab′)₂ fragment inhibited C1s activity with equal activity. Incontrast, the TNT003 Fab fragment was a much less potent inhibitor ofC1s activity. Taken together, these data suggest that the potentactivity of TNT003 is related, at least in part, to the bivalent natureof the antibody (and F(ab′)₂ fragment) and that the antibodies abilityto inhibit C1s has a significant avidity component.

FIG. 44: TNT003 and the TNT003 Fab′2 fragment are more potent inhibitorsof C1s activity than the TNT003 Fab. Wells of a 96-well plate werecoated with human IgM antibodies and non-specific binding blocked usinggelatin. Human serum (final concentration 1.25%) was added to the wellsin the presence or absence of increasing concentrations of TNT003 orF(ab′)₂ and Fab fragments of TNT003 and incubated for 1 h at 37° C. Theamount of C4 deposited on the plate was measured using a biotinylatedanti-human C4 antibody and a streptavidin-HRP conjugate.

Example 14 TNT003 Binding Characteristics

To determine whether TNT003 could bind C1s under reducing andnon-reducing conditions, western blots on SDS-PAGE gels were performedwith reduced and non-reduced activated human C1s. As shown in FIG. 45,TNT003 only binds to C1s under non-reducing conditions, consistent withthe antibody binding to a conformation specific epitope within C1s.

FIG. 45: TNT003 specifically binds human C1s under non-reducingconditions. Activated human C1s was fractionated by SDS-PAGE underreducing and non-reducing conditions and western blotted with TNT003.TNT003 only binds C1s under non-reducing conditions suggesting that itbinds to a conformation dependent epitope.

To determine whether TNT003 inhibits complement C2 or complement C4activation, purified C1s was incubated with C2 or C4 in the presence orabsence of TNT003. As shown in FIG. 46, TNT003 specifically inhibitedC1s activation of C4 but not C1s activation of C2, consistent withTNT003 being a competitive inhibitor of C4 binding to C1s rather than aninhibitor of the C1s serine protease domain.

FIG. 46: TNT003 inhibits C1s activation of complement C4 but notcomplement C2. Purified human C1s was incubated with either humancomplement C2 or human complement C4 for 3 h at 37° C. Reaction productswere separated on SDS-PAGE gels. TNT003 specifically inhibitedactivation of human complement C4, but not complement C2, by human C1s.

Example 15 C1s Determination

C1s levels were measured in patient samples by ELISA. High bindingplates (Costar, 3590) were coated with 100 μl of 5 μg/ml rabbitpolyclonal antibody to C1s (Abcam, ab87986) in 1×dPBS (LifeTechnologies, 14190-144) overnight. Blocking was performed by adding 1%gelatin (Sigma-Aldrich, G2500) in 1×dPBS for 3 hours. These plates werethen stored at 4° C. Prior to use, the plates were incubated at 37° C.for 15 minutes. After washing the plates with Buffer A (1×dPBScontaining 0.01% Tween 20, and 20 mM EDTA), serially diluted human serumin Buffer A or purified C1s in Buffer A was added to the wells. Afterincubating for 1 hour at ambient temperature, the wells were washedthree times with buffer A. Each well was incubated with 100 μl of 1μg/ml biotinylated TNT003 (diluted in Buffer A) for 1 hour then washedthree times with buffer A. The wells were further incubated with 5000fold diluted streptavidin-coupled horse radish peroxidase (HRP)(SouthernBiotech, 7100-05)(diluted in Buffer A) for 10 minutes. Afterwashing four times with buffer A, enzymatic color development wasachieved using TMB (Thermo Scientific, 34029) and the reaction wasstopped using 1 M sulfuric acid. The absorbance at 450 nm was measured.

The results are shown in FIG. 47. FIG. 47 compares the C1sconcentrations in the plasma samples of healthy volunteers (green; n=13)versus CAD patients (gray; n=27). It was found that, on average, C1sconcentrations were comparable between healthy individuals and CADpatients. These data provide a rationale for using similar dose levelsand dosing regimens for a C1s inhibitor to obtain target coverage ineither healthy or CAD patients in Phase I trials.

While the present invention has been described with reference to thespecific embodiments thereof, it should be understood by those skilledin the art that various changes can be made and equivalents can besubstituted without departing from the true spirit and scope of theinvention. In addition, many modifications can be made to adapt aparticular situation, material, composition of matter, process, processstep or steps, to the objective, spirit and scope of the presentinvention. All such modifications are intended to be within the scope ofthe claims appended hereto.

What is claimed is:
 1. A humanized antibody that binds complement C1sprotein and comprises light chain CDRs of an antibody light chainvariable region comprising amino acid sequence SEQ ID NO:7 and heavychain CDRs of an antibody heavy chain variable region comprising aminoacid sequence SEQ ID NO:8.
 2. The humanized antibody of claim 1, whereinthe humanized antibody comprises a humanized light chain frameworkregion.
 3. The humanized antibody of claim 1, wherein the humanizedantibody comprises a humanized heavy chain framework region.
 4. Thehumanized antibody of claim 1, wherein the humanized antibody comprisesa humanized light chain framework region and a humanized heavy chainframework region.
 5. The humanized antibody of claim 1, wherein thehumanized antibody comprises a heavy chain constant region of theisotype IgG1, IgG2, IgG3, or IgG4.
 6. The humanized antibody of claim 1,wherein the humanized antibody is selected from the group consisting ofa Fab fragment, a F(ab′)₂ fragment, a scFv, and a Fv.
 7. A compositioncomprising: the humanized antibody of claim 1; and a pharmaceuticallyacceptable excipient.
 8. The humanized antibody of claim 1, wherein thehumanized antibody comprises: a) a light chain variable regioncomprising a complementarity-determining region (CDR) comprising aCDR-L1 having the amino acid sequence of SEQ ID NO:1, a CDR-L2 havingthe amino acid sequence of SEQ ID NO:2, a CDR-L3 having the amino acidsequence of SEQ ID NO:3; and b) a heavy chain variable region comprisinga CDR comprising a CDR-H1 having amino acid sequence SEQ ID NO:4, aCDR-H2 having amino acid sequence SEQ ID NO:5, and a CDR-H3 having aminoacid sequence SEQ ID NO:6.
 9. The humanized antibody of claim 8, whereinthe humanized antibody comprises a light chain variable regioncomprising the amino acid sequence of SEQ ID NO:44.
 10. The humanizedantibody of claim 8, wherein the humanized antibody comprises a heavychain variable region comprising the amino acid sequence of SEQ IDNO:42.
 11. The humanized antibody of claim 8, wherein the humanizedantibody comprises a light chain variable region comprising the aminoacid sequence of SEQ ID NO:44 and a heavy chain variable regioncomprising the amino acid sequence of SEQ ID NO:42.
 12. The humanizedantibody of claim 8, wherein the humanized antibody comprises ahumanized light chain framework region.
 13. The humanized antibody ofclaim 8, wherein the humanized antibody comprises a humanized heavychain framework region.
 14. The humanized antibody of claim 8, whereinthe humanized antibody comprises a humanized light chain frameworkregion and a humanized heavy chain framework region.
 15. The humanizedantibody of claim 8, wherein the humanized antibody comprises a heavychain constant region of the isotype IgG1, IgG2, IgG3, or IgG4.
 16. Ahumanized antibody that specifically binds complement C1s protein,wherein the humanized antibody comprises a heavy chain variable regioncomprising the amino acid sequence of any one of SEQ ID NOs:39-42. 17.The humanized antibody of claim 16, wherein the humanized antibodycomprises a humanized light chain framework region.
 18. The humanizedantibody of claim 16, wherein the humanized antibody comprises ahumanized heavy chain comprising the amino acid sequence of SEQ IDNO:42.
 19. The humanized antibody of claim 17, wherein the humanizedantibody comprises a humanized light chain comprising the amino acidsequence of SEQ ID NO:44.
 20. The humanized antibody of claim 16,wherein the humanized antibody comprises a heavy chain constant regionof the isotype IgG1, IgG2, IgG3, or IgG4.
 21. A humanized antibody thatspecifically binds complement C1s protein, wherein the humanizedantibody comprises a light chain variable region comprising the aminoacid sequence of any one of SEQ ID NOs:43-45 and a heavy chain variableregion comprising the amino acid sequence of any one of SEQ IDNOs:39-42.
 22. The humanized antibody of claim 21, wherein the humanizedantibody comprises a humanized light chain comprising the amino acidsequence of SEQ ID NO:44.
 23. The humanized antibody of claim 21,wherein the humanized antibody comprises a humanized heavy chaincomprising the amino acid sequence of SEQ ID NO:42.
 24. The humanizedantibody of claim 21, wherein the humanized antibody comprises ahumanized light chain comprising the amino acid sequence of SEQ ID NO:44and a humanized heavy chain comprising the amino acid sequence of SEQ IDNO:42.
 25. The humanized antibody of claim 21, wherein the humanizedantibody comprises a heavy chain constant region of the isotype IgG1,IgG2, IgG3, or IgG4.